They drive 400 miles back the way they came. Instead of numbers, the Impala's odometer just has an infinity symbol. They track Kevin down to an abandoned church. Kevin greets them with a squirt gun full of borax. Satisfied they're not Leviathans, Kevin asks, "What the hell happened to you guys?" Dean replies wryly, "I went to Purgatory, Sam hit a dog." The Winchesters are impressed by all the demon-trapping symbols Kevin has painted around the church. He says God taught him, technically speaking. Sam suddenly remembers Kevin's message saying he escaped from Crowley. That brings us to Kevin's flashback.
He tells the brothers that first Crowley brought him to a warehouse. Kevin expects to be tortured, but Crowley just wants him to interpret another tablet for him. (The torture will probably come later.) This Word of God is all about demons. How Crowley got the tablet isn't explained. You'd think God would have made those things invisible to demons and Leviathans and so on. Kevin pores over the ancient writing, unable to make sense of most of it. Or so he says. He interprets something about a "hell gate" in Wisconsin and sets about performing a spell to open it. Crowley's minions bringing him all the ingredients he needs and then flits off to Wisconsin to await the grand opening. Kevin gets an impish little grin and lights a match. Just as the match begins to fall, Dean interrupts in the present day. "You should the King of Hell how to open a hell gate? So that all of the demons in hell come out at the same time?" Kevin gives him a confused look. "What? No!" The flashback resumes and the match lands in the bowl of Kevin's secret ingredients. A fiery shock wave incinerates Crowley's minions. Crowley is left standing in a farmyard, surrounded by cute little goats wondering where his hell gate might be.
"I told Crowley I was opening a hell gate," Kevin says in the present. "But I was reading from another chapter -- how to destroy demons." He is quite pleased with himself and the Winchesters are impressed, too. He's got the tablet stashed somewhere safe now. Sam seems oddly nervous about that. Dean asks if he was able to translate anything else off the tablet. Kevin, grinning, says he read about closing the gates of Hell forever. "Banish all demons off the face forever," he says. "That could be important, right?" Dean seems super stoked about the idea, but Sam is wary. The brothers go outside for a chat. "There's no way Kevin's getting out of this intact, is there?" Sam asks. As they argue, the conversation quickly gets back around to their own problems. Sam thinks Kevin should have a say in what happens, Dean thinks Kevin's in it whether he wants to be or not. "So... free will. That's only for you?" Sam asks. It's kind of an odd question, since Dean has usually seemed the more duty-bound one of the two and Sam did just choose to take a year off from feeling responsible for others. Dean is even more baffled than I am. He reminds Sam of the demons who killed their mother and Jess. Kevin could help them get rid of the demons forever.