Dr. Clock smiles. "A geologist, is it? How I miss my days at university, and you're from San Francisco as well, fantastic. I remember when El Presidio Real de San Francisco was first founded, in the year 1776. I am primarily a horologist myself, though I also have some knowledge of the finer points of medicine, and have made a study of what I call tempomancy-the magic of manipulating time."
He looked to the rest of you, noting the injuries some of you carry. "If you'll follow me, the boat has an infirmary where I can treat those of you in need. As it happens, we are from Earth as well."
Longhunter chimes in, staring at your clothes. "Only probably a year or few before your time, I reckon."
Her husband smiles at her before continuing. "This place is called Avision, and it is a prison. One we built to hold a monster, called Lord Sanguine at bay. To put it simply, it is linked to a physical location in the true Earth, sealed inside a dimensional bubble rich in various esoteric magics, undergoing fixed time dilation."
There is a pause. Longhunter coughs into her fist. The Doctor looks at her, confused.
"Was...that not simple?"
She shakes her head. "No, darling. As for the people you're talking about, I think we know of them. Folks like them, their ancestors probably, are what helped us trap Sanguine here in the first place. And they're probably here to free their gods, which we think he has imprisoned somewhere."