It's Friday the 13th and something sinister is about to happen: a chilling double murder in an upscale home; the evidence seems to tell a clear story until investigators discover a marriage filled with secrets and a story that doesn't add up.
After a busy dentist's (guest star Bronson Pinchot) wife dies from a form of dioxin poisoning, Detectives Goren and Eames ponder a likely set of suspects: the jealous doctor, the victim's possible online lover and a tight group of weekly trivia players. They also focus on who could have obtained the poison but their crucial clue is jealousy -- which might begin with a dead woman.