TV highlights: 'The Amish: Shunned' on PBS and 'The Biggest Loser' finale

"Winter Gold: NBC's First Look at the Sochi Olympics" (NBC at 8 p.m.) is a neat introduction to what the network has planned for the upcoming Winter Games, which begin Friday. After Spencer's board shorts revelation on "Pretty Little Liars" (ABC Family at 8), she's more determined than ever to prove her theory to the other girls, but her sleepless nights and prescription medication use make Hannah start to notice her odd behavior.