Once their joined hands were being pointedly stared at, Henry did finally let go, looking vaguely embarrassed. Mitchell moved a bit too quickly for him, and so he didn't say anything before the man was gone. But he did nod when he was welcomed, at least.

When Jack explained, Henry stared at the spot where the portal had been and let out a small 'huh.' He looked back over to Jack. "I didn't know vampires actually existed," he said, somewhat obviously. "It's kind of a relief...my world isn't the only one with, uh, strange things in it."