Later, Ellie patches up Dean's wound. She advises him to go to a hospital, but he scoffs at the very idea. He crushes cars with his body and doesn't even break out the Bengay. Their plan is to give Ellie a hex bag and send her on her way. "If Crowley can't find you, he can't sic another mutt on you," Dean says. That... doesn't seem likely. "So I'm not going to Hell?" she asks. "Not on my watch," he says. After she leaves to give the brothers some privacy, Sam points out that Ellie's soul is still earmarked for Hell. Dean thinks shutting the gates will take care of all that. So, the gates not only keep demons in, but keep souls out? But what about the souls that really belong there? Do they go to Heaven, or end up hanging out on Earth? Maybe that's the downside mentioned on the other half of the tablet.
But back to the matter at hand: Dean has a bowl of hellhound blood and the spell ready to go. You'd think a guy would take off his many shirts in preparation for bathing in something, but you'd be wrong! "The spell's not gonna work for you," Sam says. Dean ignores him and recites the four Enochian words that comprise the spell. Nothing happens. Maybe he should try the shirt thing. "Doesn't matter," he says. "We'll track down another hellhound, and I'll kill it." But Sam's already made up his mind to finish this trial, and the next two. "I wanna slam Hell shut, too, but I want to survive it," he says. "I wanna live, and so should you." He reminds Dean that he has friends, even though it wasn't all that long ago that he was pointing out just the opposite. Maybe he doesn't know Dean broke up with Benny. "You were right, okay? I see light at the end of this tunnel, and I'm sorry you don't. But it's there, and if you come with me, I can take you to it." Furthermore, he doesn't think Dean is a grunt, but a genius. "You're the best damn hunter I have ever seen. Better than me, better than Dad. I believe in you, Dean, so please, please believe in me, too." I'd argue that it's not about Dean not believing in Sam, but I can see the light at the end of the tunnel that is this episode, and I'm gonna keep aiming for it. Sad music plays. Sam and Dean give each other long, intense, pleading stares. Finally, Dean relents and hands over the spell.
Sam, still doused in black blood, recites the spell. He makes a face like something just goosed him. He falls to the floor, grunting and panting. His right arm glows from the inside. His veins stand out in silhouette. "Sammy? You okay?" Dean asks behind him. The glow dissipates. Sam catches his breath and squeezes his hand into a fist. He stands back up. "I'm good, I'm okay," he says. "I can do this." Dean looks very worried. Maybe he's worried that Sam is wrong, or maybe he's even more worried that Sam is right.