Mysteries are solved or sparked this week on TV. "Dallas" clears up J.R.'s murder, while "The Bletchley Circle" launches an investigation. Smithsonian shows us how a British university found the remains of King Richard III, and Nat Geo offers a beautiful and scary look at the issue of our disappearing glaciers. Will also get to know Ryan Lochte, a scary new teacher in "Awkward" and two brave mothers, "Mary and Martha." Here are shows to watch, or avoid, for the week of April 15-21. Curt Wagner, RedEye's Show Patrol Syfy''s messy mash-up "Defiance" premieres Monday. April TV premieres, finales and specials Want more? Discuss this article and others on Show Patrol's Facebook page.