S6·E21 Finnegan's Wake

Bayliss suffers from a recurring dream about the Adena Watson, his first homicide case and one that remains unsolved. An elderly man comes to the Homicide unit to confess to Bayliss that his father had committed a murder 66 years ago. Falsone is assigned to the case, only the case file is missing and found to be in the possession of retired homicide detective, Thomas Finnegan. Gee allows Finnegan's request to participate in the reopened investigation. Questioning the elderly man leads to the recovery of the gun that might close the case. Falsone, Finnegan, Lewis and Kellerman celebrate their potential victory as Bayliss recontemplates the Watson case.