> Not our military, not foreign country, and not aliens. That leaves…

A prototype jet owned by Lockheed and flown by a civilian test pilot. That could be called "not our military" without lying. A weather balloon launched by some civilian agency could also be "not our military."

Elves. It has to be elves.

The collective belief of Flat Earthers made it possible for them to return from the Undying Lands, but now they have a space fleet.

I suppose Silurians of some sort, hidden deep underground or under the oceans, might not exactly count as "aliens". So maybe that?

The leaked info is that there is no evidence for or against it being aliens and that it is not a domestic asset. I don’t think foreign assets have been completely ruled out but we’d better hope that’s not the explanation.

That really angry guy with the offices under a volcano. They've got lots of security in slick looking outfits.

Might also be a couple of mice, you know, the one with the gigantic head.