The Philadelphia Homicide squad shed light on another case that has been left in the dark. Lilly and the team reinvestigate the 1951 murder of a Marine who was found dead after having gone AWOL.
Freshman Rusty tries to join the most prestigious fraternity at Cyprus-Rhodes University, but his sister Casey isn't keen to have her younger brother invade her world.
Evan questions Casey's loyalty during a floor-hockey tournament; Dale helps Rusty in his quest to play with the Kappa team.
Mitch Yost thinks he has had a hallucination; a stranger arrives at the Snug Harbor Motel; police arrest Cissy; Shaun and Bill take a detour on the way to a surfing event.