"You were baptized when you were like three months old," Dean says. "In a church and everything."
Sam shrugs. "I don't remember it."
"Well, duh. You pretty much didn't do anything at that point but eat, sleep, and fill up some really stinky diapers. But I was there. You didn't even cry."
"It is a human ritual," Castiel says. "It does not bring one closer to the Creator."
"It doesn't matter," Sam says. "I still want to do it. Rituals have power; people have them for a reason."
There's a three-way standoff in a motel room that feels smaller by the second.
Finally, Dean sighs. "The Chattahoochee's not that far from here. If we go at night, nobody should be around."
They drive up Roswell Road until they get to the river crossing. There's a little recreation area on the Roswell side; Dean parks the car and they walk down the uneven banks, not terribly far, just enough that they're not readily visible from the bridge.
They leave their shoes and socks a few feet from the water's edge and wade in about thigh-deep. There's a silence, broken only by the occasional noise of traffic; then Castiel nods at Dean and says, "Take hold of him."
Dean looks skeptical, but no more so than he has for this entire process. He puts his hand on Sam's shoulder.
Castiel shakes his head. "It must be direct contact, and you must maintain it when he goes underwater. In case he burns."
"In case he what?" Dean demands.
"What happened to 'it is a human ritual'?" Sam says, voice level.
"You said yourself that rituals have power," Castiel responds.
"This is bullshit," Dean mutters, but he moves his hand to Sam's upper arm, just below the sleeve of his T-shirt.
"Kneel," Castiel says.
Castiel cups river water in his palm and blows on it gently. There's another pause, stillness, and then he turns his hand to let the water fall onto the top of Sam's head. Dean doesn't realize he's holding his breath until the water runs down Sam's forehead, doing nothing but getting him wet.
"Do you believe in God?" Castiel asks.
"I do," Sam answers.
"Do you reject evil and the works of evil?"
"Do you repent of your sins?"
"I repent of my sins," Sam says softly.
"Will you live a blameless life?"
Sam hesitates, then answers, "Probably not. But I'll try."
Castiel puts a hand on his other shoulder, pushes lightly, and Sam goes under. He comes up a few seconds later, hair dripping, silty river water running down his face. Castiel brushes Sam's bangs out of the way and lets him blink the water—or the tears—out of his eyes. He's still kneeling. Castiel pours another handful of water over Sam's head and says, "Samuel Winchester, I baptize you in my father's name. Be washed of your sins and begin a new life."
"Amen," says Sam, barely audibly.
Castiel holds out a hand, and after a moment Sam takes it and lets Castiel help him up. Dean's still got a grip on Sam's arm, like the gentle current of the river might wash him away.