In Plain Sight Season 4 Episode 6 (06/12/11)
-Sarah, an Amish girl is the witness to a murder so she and her husband, Jonathan enter WITSEC.
-Sarah has trouble adjusting and Jonathan disappears after they have a fight. Turns out when Jonathan had been on his rumspringa (a time Amish teens are given to explore the outside world) he became a drug dealer and is now turning back to that life.
-Jonathan is killed by drug dealers that he never paid back in Philadelphia. Despite Mary's concerns, Sarah decides her place is back with her community.
-It's been six weeks since Marcus left and Mary finds out she's pregnant. Marshall figures it out before she tells him. Mary isn't sure what she's going to do.