A guy is making spaghetti sauce. He also has a dead body on his counter and is using he guy's guts to make the sauce. The guy is some sort of snake monster and he has a vision of Sam and Dean coming to hunt him.
Everything is burning on the stove when Sam, Dean, and Castiel arrive. Jack is there, too. So is Rowena.
They investigate the scene. There's been a rash of these types of killing.
Castiel and Dean talk about Michael while Jack goes to the bathroom. He starts coughing up blood.
Jack returns and they talk about the case.
They go back to the motel and Rowena tells them they are hunting a Gorgon.
The Gorgon finds his next victim: a trucker.
The gang shows up at the scene posing as FBI agents. There's a message left for Dean. They determine that Gorgon can't see Jack.
Rowena turns Jack into a dog in order to get anti-venom from the vet. Rowena wants to know what Sam did to Jack, but he doesn't tell.
The Gorgon is with another victim.
Sam is also on the phone with the team back at the bunker (Maggie). Where have they been all this time?
Castiel and Jack breach the house the Gorgon is at. They save the guy while the Gorgon tells a story. A fight ensues and Cas is infected. Jack tries fighting but isn't successful when Sam and Dean show up and more fighting ensues.
Dean gets knocked out.
The stuff Rowena gave them doesn't work on Cas so Jack has to use his powers. Sam can't wake up Dean who's in a dream in his mind.
They take him back to the bunker but nothing works. Jack says he can help, but Cas says no and Jack storms out.
Jack and Cas have a discussion about death.
Dean is awake but is out of control and he tells them that Michael broke out of the room in his mind. Now he's pissed.
There's a massacre in the bunker and even Maggie dies. Michael is now in Rowena.
Flashback o how Michael took over Rowena.
Jack tries to save the day. He fights Michael and wins???????
And Jack is Jack again.