"Oh my god...!" The relief from hearing that is nearly dizzying, but he manages to take a breath and straighten up, and there's a new steel in his eyes. "Yes-- no- I mean, I'm fine-" He gives Sam a grateful look, despite the circumstances. "Thank you."

And he won't wait for the other man to follow him: he looks busy enough that Martin's happy to just run ahead towards where he said Jon is, and it doesn't take much to spot him.

"Jon!"