Law & Order: Criminal Intent: Season 4, Episode 19

4 - 19: Beast

After a busy dentist's 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.