The Hunted - S1.E10

Raphael is targeted by three demon assassins. He defeats the first one readily enough. The second, Oniko, is a female demon whom he briefly confronted early in his career. She tries to deceive him into trying to kill the third assassin, Randall (from the episode Half Way). However, it's a trap, and Raphael is attached to the generators at the local electrical plant. Meanwhile, Goodwin and Sara are looking for a permanent residence and run afoul of a demonic real estate agent who locks them up. They manage to escape and, overhearing the demons' plans for Raphael, get to the plant and free him. In the final battle Raphael sends Randall back to Hell.