Sam found a way to get rid of them for almost a month at a time, a spell that lasted until the first night of the full moon.

After two years on her own, and two more as a hunter with Sam and Dean Winchester, Leah thought she’d escaped her old life at La Push. But when she’s called home to attend Jacob and Renesmee’s wedding, she brings a little company, and the stage is set for her old and new lives to collide.

The Winchesters have been subjected to a lot of things in the name of hunting, but the result of a spell-gone-wrong on their latest case is still pretty high on Dean's weird scale. While their father is out searching for a way to undo the magic, Dean's stuck in a cabin in the middle of nowhere, trying to deal with his bitchy teenage brother and his own increasingly un-brotherly feelings toward him. Who'd have thought Sammy growing a pair of giant bird wings would be the least of his problems?