S3, E5: When a prominent doctor is murdered and his wife (guest star Lisa Eichhorn) is raped, Detectives Benson (Mariska Hargitay) and Stabler (Christopher Meloni) look to the dead man's estranged and troubled son from a previous marriage and a disgruntled former patient as likely suspects. But when the same rapist attacks the dead doctor's former mistress (guest star Liza Weil), a complicated series of relationships and events begins to unfold, as both the wife and mistress face unexpected scrutiny.