There's thousands of worlds connected to this one multiversal hub. Jim doesn't know why he didn't assume there could be more than one. The thought alone is mind bending, but then, thinking of the scope of one universe is impossible enough for a human brain to take in-- imagining several and hubs to connect all of them is next to impossible.

"Well, I know a guy who's pretty handy with portals who can help you get home when you feel you're up for it."