Nichols and Stevens must discover the identity of a killer before another couple is forced to make the most difficult choice. Abel, a deranged social psychologist, forces Ted to choose whether to kill himself or his wife Linda. This is part of a series of experiments Abel is conducting to understand and vindicate his grandfather, Leon. Leon was a concentration camp survivor who was forced by the Nazis to kill himself or his wife. Abel is haunted by the choice and sets out to prove his grandfather did what anyone would have done in that situation.

Four men who have been friends since high school discover they're being blackmailed over the death of another childhood friend. When one of the four turns up dead, it's up to Nichols and Stevens to uncover the truth behind a 22 year old mystery.