S1, E16: Dr. Matt decides to re-investigate the murder of Merlyn. He also is curious when a woman checks into the hospital as Mrs. Smith. Matt soon discovers that the woman is Lucas Buck's mother and is dying because she has a brain tumor. She begins to tell Matt all about the evil of Lucas and how she wants to kill him. Matt becomes even more obsessed with destroying Lucas than ever before. Lucas is trying to persuade Judge Streeter to sign a document declaring Matt insane so that he can be put away. Matt keeps looking for answers by reading the bible, and his obsession grows more intense when he begins to build "shrine" designed to destroy Lucas.