What was it that Elias had once called himself? The beating heart of the Institute? He'd certainly implied once that if he died, the rest of the Institute would be dragged into the grave with him, but that wasn't even anywhere near the front of his mind when he saw Elias, a hair's breadth from ending Jon's own. He'd just... Reacted, in something like instinct, felt the sickening crunch of bone when he'd slammed the wrench (clumsily grabbed at when passing by some momentarily abandoned repairs in the hallway) down on his head.

He'd done it. He'd killed him. He, Martin Blackwood, was a murderer, and here he was, sitting in his victim's office.

He knows Jon is at the door before he speaks, though he has no idea how he knows. "It's all right. Come on in," he says, voice wavering slightly.