When you watch Supernatural Season 13 Episode 20 online you'll see just how far one archangel will go for revenge. Gabriel is determined to get revenge on the demigods who sold him to Asmodeus, but he quickly learns his grace his completely back when he gets wounded. He's able to track down the guys, and he asks them for help in taking down Loki, and his sons. Dean is reluctant to help out because he has seen what going after revenge can do, but Sam eventually convinces him to help out because they need to find a way to the other side. The guys are able to track down Loki to a local hotel penthouse, but are quickly greeted by Loki's two sons. Sam, and Gabriel are able to take them down, but Dean runs off to find Loki. Unfortunately, Dean quickly figures out Loki has just left a projection of himself in the room while he really goes after Gabriel. By the time Dean, and Sam make their way back down the stairs, they see Gabriel is facing off with Loki. Want to see what else happens? Go watch Supernatural online now to see the exciting conclusion.