1: EXT. STREET IN LOP

(TEGANA takes the phial of poison from his ally and stares at it.)

TEGANA: I will use it well...on all but the first of Marco Polo's water gourds, for tomorrow, the caravan sets out to cross the Gobi Desert. Now, you will follow us...and on the third night, I will walk back to you...then we're gonna ride back here to Lop, wait for two days...and then...return to the caravan...to collect the...thing of magic...that will bring the mighty Kublai Khan to his knees!

2: MARCO POLO'S JOURNAL

(The map illustrates the next stage of the journey of MARCO POLO'S caravan.)

(Again, POLO writes and narrates his journal. His words are illustrated by the image of the TARDIS once more on the back of a horse-drawn wagon with attendant Mongol bearers.)

MARCO POLO: (OOV.) I have taken charge of the travellers' unusual caravan, and set out into the Gobi Desert. The journey across this vast ocean of sand is slow and hazardous. To make matters worse, the old Doctor continually shows his disapproval of my action by being both difficult and bad-tempered.
For three days now, during which time we have covered no more than thirty miles, I have had to endure his insults.

3: EXT. GOBI DESERT (NIGHT)

(The tent has been erected on the sands of the desert.)

4: INT. MAIN TENT (NIGHT)

(Inside the main tent, IAN and BARBARA are with MARCO POLO and TEGANA. SUSAN sits quietly nearby. The three people from the TARDIS are no longer in their own clothes but, not allowed access to the TARDIS, wear Chinese clothes. SUSAN wears a two-piece robe which reaches down to the floor, the upper part of which has flower decorations, while IAN wears a jacket which is decorated in Chinese letters. BARBARA'S top is plainer in style. The DOCTOR is absent from the meal which they have just finished. PING-CHO, again carrying out her serving duties, pours some water for IAN.)

IAN: Thank you, Ping-Cho.

(He drinks.)

IAN: How much water does a caravan like this use crossing the Gobi Desert, Marco?

MARCO POLO: We will use one barrel every five days, Ian. I have allowed for eight gourds to carry us across to the other side.

TEGANA: The bones of many men who thought they had enough lie bleached in the desert sand.

(He holds up his bowl to nervous PING-CHO and gives a curt order...)

TEGANA: More.

MARCO POLO: I think we should exercise some restraint, Tegana.

(With some relief, PING-CHO moves off. POLO turns to an upset SUSAN.)

MARCO POLO: I'm sorry the Doctor wouldn't eat with us this evening.

SUSAN: Yes, so am I, Messr Marco.

(Near to tears, she picks up the DOCTOR'S plate.)

SUSAN: I'll take him his food.

(SUSAN takes the plate behind a partition into the DOCTOR'S section of the tent. MARCO POLO brings out a chessboard from one of his travel bags.)

MARCO POLO: A game of chess, Ian?

IAN: Oh, well I'm not very good, but I'll give you a game.

MARCO POLO: I gladly accept your challenge.

(MARCO POLO sets up the chessboard. BARBARA is intrigued by the intricately carved wooden pieces.)

BARBARA: What magnificent pieces!

MARCO POLO: Yes, I purchased them in Hormuz, on my first journey to Cathay. Now they go with me everywhere. Do you, er, play...?

(At that moment, SUSAN, still upset, returns with the untouched plate...)

SUSAN: I'm sorry, Messr. Marco...

(She suddenly starts to rush from the tent. BARBARA watches her go but before she can do anything, TEGANA, seemingly oblivious to what has happened, speaks to BARBARA with unusual courtesy...)

TEGANA: Do you play chess, lady?

BARBARA: Not very well, Tegana.

(BARBARA, concerned with SUSAN'S sudden departure, decides to follow the girl.)

BARBARA: Excuse me.

(She walks from the tent. IAN and MARCO POLO prepare for their game of chess. TEGANA watches them with interest.)

TEGANA: I find it a fascinating game of...strategy of w*r. Two equally balanced armies deployed upon a field of battle, and each commander determined to be the one who cries "Shahmat".

IAN: (Puzzled.) Shahmat? Checkmate?

TEGANA: (Quietly.) It means the king is d*ad.

5: EXT. MAIN TENT (NIGHT)

(BARBARA finds SUSAN standing outside the main tent. She is still clearly upset. There is a strong wind starting to blow.)

BARBARA: We'll get the TARDIS back, Susan.

SUSAN: Yes, but at Kublai Khan's Court, when it's too late.

(She stares sadly up into the stars in the night sky.)

SUSAN: We should be up there - another time, another galaxy.

BARBARA: Oh, we'll think of something.

SUSAN: How? Ian playing chess with Marco? Grandfather being rude and sulking by himself?

BARBARA: Oh, I didn't know he's sulking, is he?

SUSAN: Well, he won't eat. He won't even talk to me.

BARBARA: Well, you know him better than I do. But I'd have said he was just feeling defenceless. He has a wonderful machine, capable of all sorts of miracles, and it's taken away from him by a man he calls a primitive. Look, TARDIS is the only home we have at the moment, and when we're in it, we feel safe and secure. But when we're out of it...

(She looks out across the desert and sighs.)

SUSAN: Will he talk to me? Confide in me?

BARBARA: Oh, he's like a rubber ball. He'll come bouncing out of there soon full of ideas.

(SUSAN stares back at the sky.)

SUSAN: One day, we'll know all the mysteries of the skies...and we'll stop our wandering...

BARBARA: Then you and I will say good-bye.

SUSAN: (Surprised.) Hum? Oh, not yet. Not for a long time!

BARBARA: Well, I think we should say goodnight anyway.

SUSAN: Are you coming?

BARBARA: No, not for the moment.

SUSAN: Goodnight.

(SUSAN runs back towards the main tent.)

6: INT. MAIN TENT (NIGHT)

(SUSAN appears in the tent. The chess match is in progress and IAN, POLO and TEGANA stare intently at the board...)

SUSAN: Ping-Cho?

MARCO POLO: Shh! She's gone to bed.

SUSAN: Oh, well...I'll go too then. Goodnight.

IAN: Goodnight, Susan.

MARCO POLO: Sleep well.

(As SUSAN leaves to go to her room, MARCO POLO turns back to the chessboard.)

MARCO POLO: Now, what was I about to do? Ah yes...

(He moves a piece.)

IAN: Ouch!

7: INT. TENT. PING-CHO AND SUSAN'S ROOM (NIGHT)

(SUSAN enters the room she shares with PING-CHO and sees that the young girl is not yet in bed but staring out of a side-flap in the tent.)

SUSAN: Not asleep yet?

PING-CHO: No, I was thinking.

SUSAN: What about?

PING-CHO: How peaceful it is in the desert.

(SUSAN joins her and looks out.)

8: EXT. MAIN TENT (NIGHT)

SUSAN: Oh, it's a lovely night!

PING-CHO: The moon will rise later. That is the time to see the desert. It is like a great silver sea.

SUSAN: (Almost to herself.) The metal seas of Venus...

PING-CHO: Where?

SUSAN: Oh, a long way from here. I've never seen a moonlit night. How long before the moon rises?

PING-CHO: Two or three hours. I'll call you then.

9: INT. MAIN TENT (NIGHT)

(In the main tent, the sight of the Gobi Desert at night has also captivated BARBARA. She returns to the three men and their chess game.)

BARBARA: Night in the desert is very beautiful.

MARCO POLO: Don't be deceived by it, Miss Wright. The desert is always dangerous.

(IAN is concentrating on the chess game.)

IAN: Like my Queen!

(He moves a piece, still watched intently by TEGANA.)

IAN: Check!

TEGANA: Oh, Marco, can you save your King?

MARCO POLO: I think so, Tegana.

(MARCO POLO studies the board carefully before making a move.)

MARCO POLO: Check.

10: EXT. MAIN TENT (NIGHT)

(Later on that night, when the rest of the camp is silent, SUSAN and PING-CHO emerge through the flap from their room in the tent. The moon has risen, and the two girls view the illuminated desert in amazement.)

SUSAN: (In wonder.) Oh crazy! Hey, Ping-cho...!

PING-CHO: Shh! The guard will hear you. (Puzzled.) Crazy?

SUSAN: Hmm? It means I dig it. You know - like it.

PING-CHO: This language of yours is very strange.

(At that moment, TEGANA emerges from the main tent. He has a brief conversation with one of the Mongol bearers, and then moves off into the desert.)

PING-CHO: Tegana!

SUSAN: Let's follow him.

PING-CHO: He will be angry!

SUSAN: You're not afraid?

PING-CHO: No, I am not. Come.

(They follow TEGANA into the desert.)

11: INT. MAIN TENT (NIGHT)

(IAN and MARCO POLO are sleeping in the main area of the tent on makeshift beds. Outside, the sounds of the horses becoming restless can be heard. The whinnying of the horses eventually wakes MARCO POLO. He gets up and moves to the doorway. IAN also wakes.)

IAN: What is it, Marco?

MARCO POLO: The horses are very restless.

(IAN gets up and the two of them move outside as the horses whinny again.)

12: EXT. MAIN TENT (NIGHT)

(They peer across the desert.)

MARCO POLO: There's a sandstorm coming, Ian.

IAN: How do you know?

MARCO POLO: Notice how still it is - as if everything were waiting.

(There is another whinny.)

MARCO POLO: They sense it too.

IAN: Will it be a bad one?

MARCO POLO: Bad enough. I must attend to the horses.

(He moves off.)

13: EXT. DESERT (NIGHT)

(SUSAN and PING-CHO continue following TEGANA through the desert. They are finding it difficult to keep up with the pace TEGANA is setting over the high dunes and deep furrows of sand, and are beginning to lose the w*rlord.)

SUSAN: He walks so quickly. Can you still see him?

PING-CHO: Yes. There he is, over there.

(PING-CHO points out into the desert. Suddenly, SUSAN sits on the ground in exhaustion.)

SUSAN: Oh, let's give up.

PING-CHO: Who is afraid now?

SUSAN: No, I'm not afraid. It's...it's just that it's so hot. I can hardly breathe.

PING-CHO: Yet it was most pleasant when we left the caravan.

(SUSAN gets up.)

SUSAN: Oh, come on, let's go back.

PING-CHO: All right.

(They start to clamber back over the dunes.)

PING-CHO: Susan, listen!

(SUSAN does so, and manages to hear the faint sounds of swirling wind. SUSAN suddenly sees something.)

SUSAN: What's that?

PING-CHO: Where?

(SUSAN points towards a hazy mist on the horizon as the wind starts to get louder.)

SUSAN: That cloud on the horizon.

(PING-CHO sees the ominous clouds of billowing sand.)

PING-CHO: Susan, it's a sandstorm!

SUSAN: What! It's coming this way! Ping-Cho, we must get back before it reaches us!

PING-CHO: No, the caravan is too far away!

(SUSAN tries to drag her away.)

SUSAN: (Shouts.) No, come on! We must get back. We can't stay here!

PING-CHO: (Shouts.) No, we'll get caught in it - and we'll never find our way!

SUSAN: (Shouts.) Ping-Cho, come on!

PING-CHO: (Shouts.) No, we must shelter here.

SUSAN: (Shouts.) No!

(The wind begins to fiercely swirl around them.)

PING-CHO: (Shouts.) !

(The two girls hold on to each other as they are caught in the sandstorm.)

SUSAN: (Shouts.) Ping-Cho! !

PING-CHO: (Shouts.) !

(Their cries and the sound of the blasting wind mingles with the noise of the "singing" sands which manifests itself as a series of shrieks and babbles.)

14: INT. MAIN TENT (NIGHT)

(Back at the main tent, BARBARA is woken by the sounds of the approaching sandstorm, and appears from her section of the tent. IAN and MARCO are back inside.
They have to shout to make themselves heard over the shrieks of the storm.)

BARBARA: (Shouts.) Ian, what is it? What's happened?

IAN: (Shouts.) Don't be afraid, Barbara. It's a sandstorm.

BARBARA: (Shouts.) But the...

IAN: (Shouts.) It sounds as if all the devils in hell were laughing!

MARCO POLO: (Shouts.) It's the wind shifting the sand!

BARBARA: (Shouts.) It's terrifying!

MARCO POLO: Not always, Barbara. Sometimes it sounds like musical instruments being played - the clashing of drums and cymbals. I've heard it sound like a great many people talking as they travelled across the desert. It can also be like a...like a familiar voice calling your name. You're not the only one to be afraid. Travellers of the Gobi Desert have good reason to fear the singing sands, Barbara.

(MARCO walks off. IAN looks towards the DOCTOR'S room in the tent.)

IAN: (Shouts.) It's fantastic that the Doctor's still asleep!

(MARCO rushes back.)

MARCO POLO: Tegana's not here! His bed's empty!

IAN: (Shouts.) What?!

MARCO POLO: Has anyone seen him?

IAN: Well, he can't be out in this!

MARCO POLO: He must be!

BARBARA: Well, what will happen to him?

MARCO POLO: If he finds shelter, he'll be all right!

BARBARA: Well...well, can't we do anything?

MARCO POLO: Nothing.

(IAN and MARCO POLO listen helplessly as the sand swirls outside.)

BARBARA: I think I'll see if the girls are all right...

(She goes towards the girl's room.)

15: INT. TENT. PING-CHO AND SUSAN'S ROOM (NIGHT)

(She sees that the room is empty.)

BARBARA: Ping-Cho!

16: INT. MAIN TENT (NIGHT)

MARCO POLO: (To IAN.) Tegana's no fool. He can look after himself. Don't worry...

(BARBARA runs back from the girl's room in a hysterical condition.)

BARBARA: (Shouts.) They're gone...they're not there!

IAN: (Shouts.) Gone?

BARBARA: (Shouts.) Their beds are empty!

(BARBARA rushes for the door. IAN and MARCO POLO hold her back and she struggles in their grasp.)

IAN: (Shouts.) Wait!

MARCO POLO: (Shouts.) No!

IAN: (Shouts.) Barbara!

MARCO POLO: (Shouts.) Barbara, you can't go out there!

BARBARA: (Shouts.) Let go!

MARCO POLO: (Shouts.) Barbara, you'll be lost in seconds!

BARBARA: (Shouts.) !

IAN: (Shouts.) Calm down, Barbara! Marco is right - there's nothing we can do!

BARBARA: (Shouts.) The girls!

IAN: (Shouts.) We must wait until the storm blows itself out!

MARCO POLO: (Shouts.) There's nothing we can do now!

(BARBARA rounds on POLO, sobbing.)

BARBARA: (Shouts.) Oh, it's all your fault anyway! If you hadn't kept us prisoner here, none of this would have happened!

(The babbling and shrieking of the storm reaches a new crescendo.)

17: EXT. DESERT (NIGHT)

(SUSAN and PING-CHO huddle closer to one another as the sandstorm billows around them. SUSAN thinks she can hear her name being called with the chatters and shrieks. The voice she hears is deep and booming...)

VOICE: Ssuuuuuussssaaaaaaaannnnnnnn!

SUSAN: Ping-Cho, what's that?

VOICE: Ssuuuuuussssaaaaaaaannnnnnnn!

SUSAN: (Shouts.) There it is again...It's Ian...I can hear him!

(An insane monkey-like babble echoes through the storm.)

VOICE: Ssuuuuuussssaaaaaaaannnnnnnn!

SUSAN: (Shouts.) It's Ian!

PING-CHO: (Shouts.) Susan, it isn't! It's the desert saying it!

SUSAN: (Shouts.) It is! It's Ian! Ian!

(SUSAN pushes PING-CHO away and tries to scramble up a dune.)

SUSAN: (Shouts.) Ian! Ian, we're here! Ian!

(She suddenly sees a shadow looming over her from out of the sand. She screams...)

18: INT. MAIN TENT (NIGHT)

(IAN waits impatiently for the storm to pass.)

IAN: How soon can we go and look for them?

MARCO POLO: Not until it's light.

IAN: Let me go as soon as the storm's over!

MARCO POLO: Ian, you'd miss them in the dark. You must wait till it's light!

19: EXT. DESERT (NIGHT)

(SUSAN recognises the figure as TEGANA. The w*rlord looks down at the two cowering girls.)

20: INT. MAIN TENT (NIGHT)

(The storm has passed. IAN, BARBARA and MARCO POLO wait in the main tent. BARBARA is frantic with worry and impatience.)

BARBARA: (Shouts.) We can't just go on sitting here!

(IAN looks towards the DOCTOR'S room.)

IAN: Shh! The Doctor's still asleep. We don't want him to know about the girls.

MARCO POLO: Barbara, I give you my word that until we find the girls, we will not leave this place.

(The group looks up, startled, as TEGANA, SUSAN and PING-CHO enter the tent. BARBARA jumps up and rushes to SUSAN.)

BARBARA: Susan! Do you know you had us half-worried to death. Where've you been?

SUSAN: (Quietly.) We went for a walk.

BARBARA: A walk!

MARCO POLO: (Furious.) Without asking me?! Don't you dare do that again! Do you understand? That also applies for you, Ping-Cho.

SUSAN: I'm sorry, Messr Marco. Has...has Grandfather been very worried?

IAN: Luckily for you, he's been asleep the whole time.

MARCO POLO: And we don't want him to know anything about this.

(He looks at the Mongol w*rlord.)

MARCO POLO: I'm surprised that you'd encourage such a venture, Tegana.

TEGANA: (Surprised.) Ahh...they weren't with me! I found them - crouched behind a sand dune.

MARCO POLO: (Puzzled.) You were alone?

TEGANA: (Nonchalantly.) Ah, well, it was a pleasant night. I decided for a walk. I told the guard - he knew all about it.

MARCO POLO: (Sternly.) In future, the guards will be told to notify me immediately if any of you wish to leave the camp.

(He looks at the bedraggled girls.)

MARCO POLO: Now go and change, we have to break camp soon.

SUSAN: Yes, Messr Marco.

(SUSAN and PING-CHO walk off. BARBARA approaches MARCO POLO who is starting to pack his things.)

BARBARA: This has been a terrible experience for us all, Marco. Couldn't we spend one more night here?

MARCO POLO: I'm sorry, Miss Wright.

BARBARA: But surely one day can't make all that much difference?

MARCO POLO: One day without progress is one day's water wasted. And in the Gobi Desert, that could mean the difference between life and death.

(Behind them, TEGANA walks back outside unseen...)

21: EXT. MAIN TENT (NIGHT)

(Outside, he removes the phial of poison from his pocket. He studies the poison carefully.)

22: MARCO POLO'S JOURNAL

(MARCO POLO writes in his journal. The map illustrates their place in the desert.)

MARCO POLO: (OOV.) Progress today has been good, although we were all very tired after a sleepless night. How can I ever repay Tegana for saving Ping-Cho and Susan? We covered fifteen miles before I gave the order to set up camp for the night.

23: INT. TENT: PING-CHO AND SUSAN'S ROOM (NIGHT)

(SUSAN is frantically brushing her hair as PING-CHO enters.)

PING-CHO: Susan! Susan!

(SUSAN continues brushing.)

SUSAN: I can't get this sand out of my hair.

PING-CHO: Last night there were moments when I was sure I would never be here again.

(PING-CHO settles down in her bed. SUSAN finishes her hair and lowers her voice...)

SUSAN: Ping-Cho, did you believe Tegana last night, when he told Messr Marco about going for a walk?

PING-CHO: Why not?

SUSAN: Well, I don't think Tegana's the kind of man who goes for a walk just because it's a nice night. I think he goes because he has a reason to go.

PING-CHO: Susan, why would he lie to Messr Marco?

SUSAN: I don't know!

PING-CHO: He's an important man - the special emissary of the great Mongol leader who has been at w*r with Kublai Khan. Tegana is to arrange a peaceful settlement between them. Would a man like that lie about walking in the desert?

SUSAN: No! No, he wouldn't. That's what's so strange...

PING-CHO: What?

SUSAN: The fact that he did.

24: INT. MAIN TENT (NIGHT)

(In the main tent, TEGANA is polishing his sword, while MARCO POLO writes in his journal.)

TEGANA: What is that you do?

MARCO POLO: I keep a journal.

TEGANA: Why?

MARCO POLO: Because it interests me.

(MARCO POLO continues to write. Suddenly, TEGANA yells out POLO'S name...)

TEGANA: Marco!

(...and lunges at MARCO POLO with his sword. POLO reacts quickly to parry the blow.)

TEGANA: (Admiringly.) That's excellent, excellent! But it's better a man keeps the blade of his sword clean...than its edge sharp. You continue your writing, Marco. I'll see to the horses tonight.

(He heads for the door.)

TEGANA: I'll, er, I'll give the guard his instructions.

MARCO POLO: No! Send him to me.

(TEGANA hesitates.)

MARCO POLO: Please.

(TEGANA leaves.)

25: EXT. THE WATER WAGON (NIGHT)

(Once outside the main tent, TEGANA walks towards the wagon containing the water gourds. There is a guard there. TEGANA whistles and this draws the guard away. TEGANA then moves to the back of the wagon and s*ab each gourd with his sword. The precious water splashes all over the ground.)

26: EXT. THE WATER WAGON

(The next morning, IAN, MARCO POLO and BARBARA survey the damage caused to their water supply.)

IAN: All of them, Marco?

MARCO POLO: Yes, except for the one we're using.

(They walk round the wagon and look over the gourds.)

IAN: How much is there left?

MARCO POLO: Without rationing, enough for today.

IAN: And with rationing, how long will it last?

MARCO POLO: Three - four days.

BARBARA: Is there enough to get us back to Lop?

MARCO POLO: If we're very careful with it, yes.

IAN: But who could have done it?

MARCO POLO: Bandits, Ian.

BARBARA: (Surprised.) Bandits? In the desert?

MARCO POLO: Yes, this has happened before, but not to me. The bandits follow a caravan out into the desert. Then one night, this happens. The caravan is forced to turn back. Then, when everyone is weak through lack of water, the bandits att*ck.

IAN: So if we turn back, we're bound to be att*cked.

MARCO POLO: Yes.

(TEGANA silently joins the group having heard this exchange.)

TEGANA: Then we shall fight.

IAN: There must be somewhere else we can go to?

MARCO POLO: The nearest is a small oasis, but that's one week's journey north from here.

IAN: Marco, if we pressed really hard, walked day and night, how long would it take us?

MARCO POLO: Five, possibly six days.

IAN: As long as that?

MARCO POLO: Yes, and with the water rationed we'll be growing weaker all the time. There is another danger, Ian - bandits always camp near an oasis.

BARBARA: Well, then we must go back to Lop.

IAN: But they're bound to be waiting for us there! No, we must go north, and take a chance.

MARCO POLO: Yes, what Ian says makes sense. We go to the oasis.

TEGANA: We shall all die of thirst. I will not go.

MARCO POLO: Then what will you do?

TEGANA: Return to Lop. I'm not afraid of any bandits. Just give me my share of the water...

MARCO POLO: (Interrupts.) No, Tegana.

TEGANA: (Quietly menacing.) You refuse the w*rlord Tegana?

MARCO POLO: I am commander of this caravan, and I am responsible to Kublai Khan for your safety. We go north, together.

(Defeated for the moment, TEGANA stares at POLO...)

27: MARCO POLO'S JOURNAL

(The map shows the slow progress that the caravan is making.)

MARCO POLO: (OOV.) Have I made the right decision? Each day, our progress towards the oasis becomes less. On the first day, we covered twenty miles. On the second, fifteen. The third, ten. The fourth day's total was eight. Now on the fifth day we have travelled only two miles before the heat of the sun has forced us to stop. We are nearly exhausted, and our situation is perilous...

28: EXT. DESERT. CAMP

(The sun continues to b*at down relentlessly on the caravan. The weary travellers, now including the DOCTOR, lie motionless in the shade of the wagons underneath an awning gazing out across the merciless baking sands. MARCO POLO comes along and shares out the last few drops of water.)

MARCO POLO: The worst of the sun is nearly over. We must move on again as soon we've had this.

(Everyone drinks his or her water in silence. They are all seriously affected by heat exhaustion.)

IAN: Have the bearers had their ration?

(MARCO nods and pours IAN his water but the ration runs out before MARCO can take his.)

IAN: You take it.

MARCO POLO: We will share.

(IAN accepts the offer and drinks.)

DOCTOR: Marco, is this all we're going to get until tonight, mm?

MARCO POLO: Until we reach the oasis, Doctor, yes.

DOCTOR: Mmm.

BARBARA: There's no more?

(MARCO shakes his head.)

TEGANA: How much further?

MARCO POLO: I cannot say.

TEGANA: I will go to the oasis and bring back water.

(TEGANA stands and starts to stumble towards where his horse is reined.)

MARCO POLO: Do you think you could reach the oasis?

TEGANA: Yes, my...my horse is still the strongest.

(POLO considers.)

MARCO POLO: Very well, Tegana.

(TEGANA stumbles away but stops for a last word...)

TEGANA: You, er, wait for me here.

MARCO POLO: No, while we can, we'll push on towards the oasis.

(TEGANA considers...)

TEGANA: Right.

(TEGANA leaves to fetch his horse. IAN calls out weakly after him.)

IAN: Good luck, Tegana...

MARCO POLO: We must go.

(The group gets up and prepares to leave.)

DOCTOR: Susan...help me up...

(Suddenly, as SUSAN helps him, the DOCTOR collapses unconscious.)

SUSAN: Oh, Grandfather!

(IAN rushes over to assist.)

SUSAN: What's the...what the matter with him?

IAN: He's exhausted.

MARCO POLO: We'll fix up a cot for him in the wagon.

BARBARA: To be jostled and bumped about? He needs to rest in comfort, Marco. What about the TARDIS?

(POLO hesitates...)

IAN: He'd be more comfortable, Marco.

(Still he doesn't answer. The three companions of the DOCTOR look at him pleadingly.)

SUSAN: Please, Messr Marco!

(POLO reaches a decision with reluctance.)

MARCO POLO: Very well. The Doctor can travel in his own caravan. Susan, you can go with him. But you, Barbara, and you, Ian, must remain with me.

IAN: Thank you.

(He takes POLO to one side in order that the others don't hear him.)

IAN: Marco...without water, the Doctor isn't going to last twenty-four hours.

MARCO POLO: None of us are, Ian - without water. (Sighs.) Our fate rests with Tegana.

29: EXT. OASIS

(TEGANA has arrived at the oasis and is greedily drinking the water. Behind him are the remains of man-made structures – posts standing starkly against the desert sky. He fills a water gourd, and stands, triumphantly holding it to the sky.)

TEGANA: Here's water, Marco Polo!

(He tips the gourd and pours the contents over the sand by the pool.)

TEGANA: Come for it!
{"type": "series", "show": "Doctor Who", "episode": "01x15 - The Singing Sands"}