"Hm." It's a sound of agreement really; he had inferred a great deal but being wrong didn't concern him. That Adrian was willing to correct him still provided the information he'd been looking for.

Although it's still strange to hear and there's a flicker of confusion in his expression to hear that Adrian would have wanted to help. That he was worried.

He is the last to say he's good at reassuring anyone, and the majority of the time he wouldn't even try. But he does make some attempt in acknowledgement of all Adrian has done for him.

"Fire wouldn't be enough. A stake isn't enough. You don't have to worry about that."

See, reassuring.