"Yeah, one shot is enough for a few hours, he said," Derek tells him, smiling when Bitty takes the vial. He bites his lip at the question, looking down at the vial.

"He gave me eight shots, but you're the first person I've asked," Derek admits, looking sheepish. "Everyone who took it at the party was fine, and Magnus-- I know he can be kind of an ass, but he gave this to me as a gift. Like he knew how much it would mean to me. And Luke trusts him, and I trust Luke."

It's kind of a thin argument, and Derek's shoulders droop a little. "It's completely up to you if you want to try it."

He smiles a little, almost teasingly. "But if something were to happen to you, I'd do my best to rip Magnus' throat out, just so you know."