When a robbery suspect is brought in by Wojo, the detectives soon discover he is in the witness protection program after testifying against the mob. After he and Dietrich get shot at while on a call, Harris realizes his partner saved his life and starts acting strangely as a result.

The men of the twelfth precinct are working the graveyard shift and have to deal with several crises, one of which includes a bomb threat downstairs and an insomiac who caused a disturbance at a nearby drugstore.