S03E15: 'Time Is On My Side'

As time runs out for Dean, Sam convinces him to head to Eerie, Pennsylvania to investigate a possible zombie case.

Instead, they discover Doc Benton, a real-life doctor who, in 1816, abandoned his medical practice to follow his obsession with finding the key to eternal life by drugging people and stealing their vital organs.

Meanwhile, Bobby finds out where Bela is hiding and Dean heads out to confront her, leaving Sam behind to deal with the good doctor.

Dean and Bela battle it out for the last time, and Dean leaves Bela in a desperate - and possibly fatal - position.