"Marvel's Agents of S.H.I.E.L.D." (8 p.m., ABC): All aboard! The team's pursuit of the Clairvoyant lands them on a train that appears to be taking them to their death. In a brighter development, comics icon Stan Lee makes a cameo appearance.
"The Amish Shunned: American Experience" (8 p.m., PBS): This fresh documentary explores the Amish practice of shunning those who leave the faith through two young adults who left their community behind. Also included: Interviews with loyal Amish men and women who describe what their faith means to them.
"The Biggest Loser" (9 p.m., NBC): Even on a show called "The Biggest Loser," there has to be a winner. In the Season 15 finale, we find out which contestant did the best job of dealing with his or her weighty issues.
Also on Tuesday: