It's hard to focus. It's hard to think of anything except the water. But as he drinks it, a coolness spreads out from his stomach and finally reaches up into his mind, washing over it as if he's poured the water directly over his seething brain. It's enough for him to fight through it and listen to Remus—calm, patient Remus, Remus who never minded him—and open his eyes again.

"Potion." His voice still sounds raw and dried out around the edges, but it's lost that edge of hysteria. "Had to drink it. He set the trap that way. The protection." He holds the necklace up again, forgetting that Remus both won't recognize it as Slytherin's locket and won't know why it's important that they destroy it as thoroughly as they can.

He feels better, he realizes, better even than the water alone should have done, and he realizes the cuts and scrapes from the Cave are fading. Healing spells. The kindness extends beyond just water, and the magnitude of the realization settles into him that by coming to Remus he'd made the right choice for perhaps the first time in his life.