Sam and Dean discover a wood nymph living in the bunker who is determined to protect her family, at any cost.

Sam learns that former Men of Letters, Magnus, once built a magical box and Sam sets out to find it in the hopes it can cure Dean of the Mark…

Sam and Dean track down the missing Crowley and discover that he’s now thoroughly addicted to human blood. Once they get him sober, the brothers go seeking the First Blade…

Sam and Dean discover a doctor who, back in 1816, became obsessed with finding the secret of eternal life by taking people’s vital organs. Meanwhile, Bobby finds Bela and Dean…