“A Thin Layer of Rock” – Jenny and Beau investigate the untimely disappearance of a missing groom from a wedding while Cassie enlists the help of Denise and Beau’s daughter Emily to unravel the lies surrounding Walter and Sunny Day Excursions. As the truth is revealed, Cassie finds herself in more danger than ever and Sunny makes an unlikely alliance to save her family. Then, a deadly attack at the diner changes everything on “Big Sky: Deadly Trails,” WEDNESDAY, DEC. 7 (10:00-11:00 p.m. EST), on ABC. Watch episodes on demand and on Hulu the day following their premieres.