An honor student dies at a party, while the primary suspect is their alcohol supplier, the four honors students who threw the party - are arrested for criminally negligent homicide, but get a slap on the wrist from Judge Donnelly. Det. Stabler enlists his own teenage daughter Kathleen to guide him through the world of teenage cyberspace to find out where the next party is taking place. The website leads to the home of one of the students, where they find the mother of one of the kids -- Lillian Rice in a compromising position, and she is arrested. The arrest and entire cyberspace scenario hits a personal nerve with Stabler.

The investigation of a bride-to-be's murder uncovers a man's double life; a turn in the case rattles Stabler, who turns to his wife and children for comfort. When Dets. Stabler and Benson speak to the girl's grief-stricken parents they discover her fiancée, a CIA agent named Stephen Dashiell, had been threatened by terrorists -- they believe this may have been a professional hit. Their difficult search for Dashiell leads them to a perfect suburban family - and then a tragedy - one that pushes Stabler to face new truths about his own family.