Unlike most stories with a twist ending (which is almost a genre unto itself in this publication), this story has two twists at the end. The man in the bathtub is a criminal who has agreed to help with an experiment. The crazy white-haired old man told him that he was going to drain his blood and replace it with a new-fangled experimental liquid that was better than blood.

Twist one: they didn’t actually drain the man’s blood because there was no blood substitute. Instead, they were running an experiment to see if they could convince a man that he was bleeding to death even if he wasn’t.

Twist two: the man died. Successful experiment, I guess.

(Heavy Metal issue #107, Spring 1986 – Page 89 The Experiment by Jimeno)