He feels an open summons and lets it grab him -
After almost ten years of singlehandedly running an industrial revolution, and trying to destroy superstition like he did chivalry, slavery, and smallpox, superstition has begun to fight back. He paces around the room in an empty Camelot, reading and re-reading the note from Clarence.
Only fifty-three Englishmen who didn't drop everything and go back to their sixth-century lives, and them besieged. The entirety of the nation in arms against them because the Church decreed it. And Arthur—the one nobleman who might truly be called noble—dead.
He paces around the room, trying to think of a rescue plan, or any plan at all with a chance of working. After for once in his life repeatedly failing to think of anything, he sees his footprints in the dust forming a circle on the oak floor.
He looks at the footprints. He looks at Hank.
"Well, this looks hilariously accidental," he says.
"Who are you, and how did you get in here?" The door wasn't locked, but it is noticeably across the room from the newcomer.
"My name is Cam, and you summoned me. Hilariously accidentally, it would seem. Do you need a demon for anything, as long as I'm here?"
"A demon? I should warn you," Hank's demeanor changes, "I am the most powerful magician in existence at the moment. The charlatan Merlin will admit I once removed a demon that he pronounced impossible."
"...I would be very impressed with this feat of hocus-pocus if I didn't know how summoning worked. If you just want to get rid of me, go ahead, I'll go home and catch up on my reading and try not to be too mopey about how not even accidental non-binding summoners appreciate my commitment to nonviolence."
"A commitment to what? You're the first person I've met in years who didn't take violence as a divinely ordained fact of life. Until I told them otherwise, anyway. Are you sure you're a demon?"
"Are the wings not a dead giveaway? And the tail? Where is this, anyway?"
If you are, though, I'm quite prepared to, uh, smite you with thunder from on high."
"And, just to clarify, are you a historical reenactor such that actually if I hop out the window and fly for a while I will find skyscrapers and spaceports and such?"
"Skyscrapers? No, not yet I'm afraid; I haven't got that far. How do know about those, anyway? And what's a spaceport?"
"And of course you happen to end up in a room with me. Unless everyone here is secretly a time-traveler?"
That probably needed some explanation.
"I'm from 1895."
"Grand. And now you have time-travel summoning powers, aren't you proud of yourself. How did you get to 536 or thereabouts?"
Far as I know there's no way back, unless 'waking up' is an option, which it might be. I've just been trying to do the best I can with this place as I've found it."
"Okay. Seems likely to be an improvement, considering, I think they had the rudiments of germ theory and so on by 1895, etcetera. So do you need a demon for anything? ...You don't know what demons are for, do you. Demons make stuff. Arbitrary stuff. Including stuff from 2159."
Cam smiles. And conjures up a tortilla chip loaded with guacamole, which he eats. "No factories required."
"I think we've got a rescue mission to go on."
"The Republic of England. All fifty-three of its members. They can probably defend themselves indefinitely, but they're under siege and could use a miracle or two."
"...Okay, I'm less confident in 'time travel' and beginning to suspect 'alternate universe', because I think I probably would have noticed if there was a Republic in England in the five hundreds. But that's relatively immaterial. Should I replace my wings and be rid of the tail, pretend I'm an angel? Not like anyone will know the difference magically speaking unless you've got a cagey summoner."
"Definitely don't be a demon. I thought I had cured the superstition from these people, but the church has its tentacles on them tight, or else the lot of them are cowards. Anything that even makes them think the word 'demon' and they'll break out the torches and pitchforks."