I was thinking it was a movie, but now I'm wondering if it was "Twilight zone" or another show like that. A magician has made a deal with a monster, or the devil (I don't remember which, although the devil IS a monster). I think he does his regular tricks, but for his "special" trick, he lays on a slanted surface, & a slab of spikes slams against the surface, which would kill anyone else trying this, but he survives this. His secret: the "deal" he has made - he finds a victim, & lures them (to the basement?) in a triangle-shaped pyramid. When the slab of spikes hits the surface, the victim gets the spikes, & the magician is spared. At the end of the movie, Someone finds out the secret, & saves the victim. Guess what happens to the magician the LAST time he does the "trick".