I don't know...however they did it, those two slept right through being brought to another world.

[She went over to take a seat on the bed, the guinea pigs starting to stir awake at last. And, well, trying to avoid looking at the Gungnir spear next to the trident. She spotted that gun.]

...They said they couldn't control who they called, but still got our loadout prepared. You use firearms as well?