A man is attacked and killed in his car by some creature.
Crowley shows up and tells the boys that he’s in charge and has a potential lead on a case for them.
Sam and Dean find a common denominator in the attacks surrounding a particular family.
Sam thinks that one of them is a werewolf, but Dean wants to make sure before capturing them.
They follow Cal but he doesn’t transform. Instead, the family dog, Lucky, attacks Cal. Lucky transforms into a man.
Sam watches the house and discovers that Lucky is really a skin-walker. He chases after him.
Sam and Dean capture Lucky and tie him up. They learn of the Alpha Skin-Walker’s plan to create more skin-walkers.
The two wait for Lucky to meet with the pack so they can take down the leader.
An all out battle ensues and the brothers take down the pack.
Sam confronts Dean about his soulless self and admits that despite being a better hunter, he needs to get back to his old self. That’s who he truly is and he needs Dean’s help.