Two days before Halloween, Luke Wallace eats one piece of candy and ends up with four razor blades in him. And dead. Sam and Dean interview his widow, and find a hex bag hidden behind the victim's fridge. The next day, at a pre-Halloween party, a teen named Tracy bobs for apples, and gets checked out while doing so. Hoping to get the same… rise out of her audience, Tracy's friend Jenny takes a turn, and is boiled alive in the apple tub. Posing as Agents Geddy and Lee, Sam and Dean investigate the scene and find another hex bag. They ask Tracy if Jenny had any connection to Luke Wallace, but Tracy says she never heard of him.

Dean and Sam research the contents of the hex bags, which contain some pretty heavy duty stuff like long extinct plants and baby bones (oh Kripke!) and figure out that a witch must be trying to summon the demon Samhain, which requires three blood sacrifices over the course of three nights. They check out the local high school and talk to the art teacher, Don Harding, who tells them about his altercation with Tracy. Her drawings were kind of creepy and evil -- and when he told her to can it, she flipped her lid and got suspended. Along the way, they boys discover she lied about not knowing Luke Wallace, so they make Tracy as their witch.

The boys eventually meet up with Castiel, and he's got a new friend with him -- Uriel. Uriel is impressive, but utterly unimpressed by our intrepid heroes. He calls them, and all of us, "Mud Monkeys." I am so using that on my kids. Tracy's been waiting 600 years to summon Samhain, whom we're going to refer to as "Sam Hain" because that's how they say it in the episode. No. Really. And it looks like Tracy was planning to make the boys her third (and a bonus fourth?) sacrifice in as many nights, because she'd hidden a hex bag in their motel wall. The angels tell our boys that if Sam Hain rises, that will mean yet another broken seal from among the 66 needed in order for Lucifer to rise, so they order Dean and Sam to leave town so they can wipe it out. Dean and Sam refuse and argue for a chance to stop the summoning on their own. Uriel gets rude. Castiel listens to their pleas, but warns them time is growing short. Later, when Sam's alone with Dean, he confesses he's been so disillusioned by the angels and their plan, that he's having a crisis of faith. Meanwhile, Uriel suggests to Castiel that they go rogue, but Castiel says they have their orders -- to follow Dean's orders!

Sam and Dean realize that Don must be in on things with Tracy, because he's the one who knew they were looking into her. The boys find Tracy tied up and about to be sacrificed by Don. Sam and Dean shoot him, and Tracy thanks them for doing her dirty work. Don was actually Tracy's (at least 600 year old and quite annoying) brother and now she's got her third blood sacrifice. She binds the boys with some sort of spell so they can't interfere, and invokes Sam Hain who breaks through the concrete cellar floor and decides to inhabit Don's corpse. Don and Tracy kiss (Ew!) and then he snaps her neck. He doesn't see Sam and Dean because they smeared blood on their faces to fool him, just like people used to wear masks to walk around undetected by him.

The boys catch up with Sam Hain at the local cemetery, where he's busy tormenting teenagers and raising the dead. At least he's useful. Sam wants to use his mojo to take care of the demon, but Dean warns him off. When Dean has to save the tormented teens, Sam has to stop Sam Hain on his own. He tries to use Ruby's knife to kill him, but Sam Hain knocks it away. If he wants to live, Sam has no choice but to use his magical exorcism abilities, so he does. Dean arrives in time to see it in progress, to see Sam's struggle, and to see his bloody nose, afterwards.

Sam returns to their hotel and is confronted by Uriel about using the power Azazel gave to him. He explains he had no choice, but when Uriel is unmoved, Sam tells him, "You know, my brother was right about you [angels]. You are dicks." Uriel warns him that as soon as Sam stops being useful, he is history. He also says to tell his brother he should climb off his high horse. "Ask Dean what he remembers from Hell." Meanwhile, in a sunny park, Castiel reveals that the angels' orders were to follow Dean's orders, because the scenario was a test of Dean. Castiel thinks Dean passed; he at least chose the way Castiel prayed he would choose, but then Castiel admits to his own crisis of faith or at least failure of discernment. He cautions that Dean will have more decisions to make in the coming months, and Castiel does not envy the weight that is on his shoulders. The good news is Castiel thinks we're works of art. The feeling is mutual, Cas.

Next week, we travel to Wishville. I wonder if Anyanka and Halfrek will be there.