The jail entrance is massive with a huge fence. There are guards on all sides. There are barbs and dangerous things surrounding.
Jail entrance, Inside Tower
rat
guard
I am a guard at the royal castle.  I am brave and strong.  It is my duty to protect the king.
Hello what's this? Did that rat just speak? Um no.... *squeak squeak* I heard it! You really can speak can't you rat? Maybe I can, maybe I can't. What's it to you? Well this is a jail isn't it? How do I know you aren't passing information to a prisoner? A rat makes a good spy after all. Okay look, I am just here because I want some crumbs to eat. Ah I'm afraid you're in the wrong place then. You don't want any of the slop they're feeding the prisoners. I've found that there is a good deal down here, for whatever reason. Interesting. Perhaps there's been some contraband getting through...I'll tell you what. If you help me catch the smugglers, I'll give you all the crumbs you can eat. I can certainly do that, sir. How do you propose we do this? Well you're certainly small enough to slip in under the barbs and whatnot. Just go on in and sniff out any good morsels and report back where you found them. I can handle the rest. Can do, sir! Any areas to focus on?