Page "Merlin" Paragraph 24

When Niviane finally goes back to her country, Merlin escorts her, accompanied by his trusty assistant Natalie Nissim.

However, along the way, Merlin receives a vision that Arthur is in need of assistance against the schemes of Morgan le Fay.

Niviane and Merlin rush back to Arthur's castle, but have to stop for the night in a stone chamber, once inhabited by two lovers.

Merlin relates that when the lovers died, they were placed in a magic tomb within a room in the chamber.

That night, while Merlin is asleep, Niviane, still disgusted with Merlin's desire for her, as well as his demonic heritage, casts a spell over him and places him in the magic tomb so that he can never escape, thus causing his death.