At the end of the universe, or possibly all the universes, there is a bar. At a table in one corner of the bar is a tall man with a face that looks like death, savouring his second glass of something pale blue and slightly fizzy. He's sat with his back to the wall so that he can keep half an eye on the other patrons.
"Hume can't leave the area of the paratypical field, which contains—or possibly is contained by—a forest. Without the field to sustain him, he'd die." At least, he's pretty sure that's what would happen. He hasn't tested it, for obvious reasons.
"I can leave, but I've only done so once in the years I've been looking after Hume. I don't want to risk leaving him for very long. Even if I did, I have no way of getting off-planet, let alone doing so without alerting the Reigners. The Reigners themselves are presumably still back on Homeworld. They have no reason to leave, and less reason to come to Earth in particular."
Well that's distressing.
"That sounds like something I should be able to help with. At least enough to give you some more options."
"How very egalitarian of you." Mordion doesn't sound like he disapproves. "That's not a sentiment one hears expressed very often around the Reigners."