Loki is already reaching out to counter that check—there are five ways to do it, three of them with inconvenient counter-moves—but his fingers freeze above the prince (or bishop, on Earth). Where...? He pulls his hand back and directs a suspicious squint across the board at his opposition. He has an instinct for magic now, a sense of when it's being performed, and he'd felt nothing, but the piece had vanished as thoroughly as if Loki had vanished it.

So, either Reid has some flavor of magic unlike anything Loki has encountered, too different for him to detect, which seems unlikely, or he's done something else.

It's a silly instinct, but he can't stop himself from leaning over and checking the floor beneath their table. Just in case.

Then he sits up, fingers laced and chin resting on them, matching Reid's bland look and raising him one pointed interest. "Is it customary on Earth for the enemy's prisoners to simply vanish?"