(Prior to getting David to do automatic writing)
Derren: I need him to be as relaxed as possible. So to combine this with the opportunity of seeing David in a close-fitting wet suit, I've decided to give him the experience of a flotation tank.
(After Derren "regresses" David to 1938)
David: I think, probably, the scientific logic of it would indicate that Derren is a witch...I'm happy to go with that.