Gharty has a Vietnam flashback. Sheppard is placed back into rotation. Lewis asks Falsone to switch cases, as Lewis is still unsure about Sheppard's ability to be back on the street in the part of town where their call lies. Munch and MGee work a case where the victim was hit and run. One of the victim's possessions is a knife that has some meaning for Gharty, who later is able to recognize the tattoo found on the victim. Sheppard confronts Lewis about the case switch. She and Stivers talk more... after Stivers, working with Falsone, sees him "go off" on a potential witness... Munch and MGee find their hit and run vehicle, a rental SUV, whose renter claims to know nothing of the incident and says he had filed a stolen-vehicle report. Munch pulls the victim's DOD file and---for good measure---Gharty's! Munch, begins to spread doubts with the other detectives about Gharty's Vietnam experience, because the file tells him that Gharty had a less than honorable discharge. A kid, who had stol