She becomes pregnant and vows that her child will inherit Arthur 's kingdom .
Before the wedding , Arthur 's stepsister , Morgane , arrives at Camelot and seduces Arthur by taking on Guinevere 's appearance .
Guinevere becomes pregnant and vows that Guinevere 's child will inherit Arthur 's kingdom .
Before the wedding , Arthur 's stepsister , Morgane , arrives at Camelot and seduces Arthur by taking on Guinevere 's appearance .