A genetic researcher named Dr. Faye Walsh is murdered in what appears to be an attack by animal rights activists. She and her husband, Professor Donald Walsh, had both been repeatedly threatened because they worked in animal testing. But Logan and Briscoe discover the victim believed her husband was cheating on her with lab employee Susan Boyd (Frances Fisher). Dr. Walsh had hired a private detective, whose evidence supports the suggestion of an affair. Boyd and Walsh are arrested, but Walsh says there was no affair. He insists Boyd had a crush on him and he turned her down.
When the defence gets key evidence against Boyd excluded, Stone and Robinette convince her to accept a plea deal. She says that she wasn't involved in the murder; and the charges against her are dropped. But in court, Boyd's story falls apart under cross-examination. The judge instructs the jury to disregard Boyd's testimony, and Walsh is acquitted. Boyd's former employer now comes forward and reveals that she stalked him when they worked together. Furthermore, Stone discovers that Boyd has repeatedly forged her credentials and lied about her past.
Olivet assesses Boyd as being delusional; she genuinely believes that she is in a relationship with Walsh. Boyd is charged with murder when the detectives search a house she had rented and find the bullets used in the murder. Even when Walsh is brought in to confront her, she continues to believe he is in love with her. She produces a "love letter" he wrote for her - actually a note from lab security that proves Boyd knew Dr. Walsh would be working late on the night of the murder. Boyd won't accept a plea, and insists on representing herself. Since she's legally trained and very good at it, Stone questions whether the case will make it to trial.
This episode contains examples of:
- Animal Wrongs Group: The leader of such a group, who's been convicted of multiple bombings in the past, is an immediate suspect in Dr. Walsh's murder but quickly ruled out.
- Attempted Homewrecker: Boyd has, twice that we know of, gotten so delusional that married men loved her that she attempted to destroy their marriages. The second time it ended with murder.
- Murder the Hypotenuse: Boyd was so delusional that Donald Walsh was in love with her that she murdered his wife.
- No Ending: The story ends with no real conclusion, and Stone predicts that Boyd will repeatedly put up obstacles to prevent the case going to trial.
- Schiff One-Liner: This exchange between Schiff and Stone:Schiff: "The truth is ugly, so we put our prophets in prison."
Stone: Oscar Wilde?
Schiff: Charles Manson. - Stalker with a Crush: Boyd was this for Walsh and at least one previous man.
- Stalker Shrine: Boyd kept one devoted to Walsh.
- Teacher/Student Romance: The victim met her husband when she was one of his graduate students.
- Yandere: Susan Boyd. She killed her rival for love interest Donald, who does not even know her. But Susan cannot reflect reality.
