In Plain Sight Episode 4.11 Provo-cation

When a decorated soldier witnesses his superiors selling arms to the enemy and steps forward to do the right thing, he soon finds himself out of the Army, shipped off to Albuquerque, and in the Witness Protection Program. Like most witnesses, John and his wife Sue have some trouble coping with the changes, but unfortunately their problems run deeper than adjusting to life off the base: John is suffering from Post Traumatic Stress Disorder, and his psychological state is putting the case and the witnesses in jeopardy.

And if that's not enough for Mary and Marshall, these witnesses also come with extra baggage: Major Lucas Provo, a JAG lawyer who's in town to personally handle the John's case. His presence rankles Mary, until it turns out she and Provo get along better than they had originally thought. Much better, in fact. And with Marshall and Abigail preparing to take their relationship to the next level, Mary might soon find herself in need of a new source of support.