Monoliths are like buses, it seems.
Since one cropped up in a desert in Utah a couple of weeks ago they've been appearing everywhere, from the hills of California to 2,000-year-old Romanian forts.
Now, one has seemingly appeared in the sky.
Jeff Jacobs was driving home from work in Coeur d'Alene, Idaho, on Monday when he decided to pull over and snap some sunset pics for his wife Rena.
But the 56-year-old couldn't believe what then appeared before his eyes.
He said: "All of a sudden this rectangle showed up. It was only in the sky for a couple of seconds. It wasn't there, then it was, and as quickly as it appeared, it was gone again. That quick!
"I just thought 'What the hell is that?'. I'm just a north Idaho boy and we don't see things like that.
"A couple of people have suggested it could be the monolith from Utah and it is that type of shape. Utah isn't that far away from Idaho in the grand scheme of the world, the two states are connected."
Alright Jeff, you're right, the states are connected - but you haven't really accounted for the transformation of a 10ft high metal monolith into a gigantic black rectangular cavern in the sky, have you?
Jeff admits he has no way of knowing what it was though; all he knows is that it wasn't a weather balloon and there is life beyond Earth.
He said: "Others have said it looks like there are hands at the bottom holding it and I can see what they're talking about there.
"I just had no idea what I was looking at. I'm not a particularly religious person so I couldn't begin to guess. All I know is, it isn't a weather balloon.
"I don't believe we're the only beings in this universe. If people think there isn't life beyond our world, they've got to be nuts."
But while we probably won't ever know for definite what went on here, people had plenty of theories when Jeff shared the photos on Facebook.
One person commented: "As crazy as it sounds, the monolith in Utah just disappeared and if u look at the picture u took and the shape of both the monolith and the that shape, the two almost have the same similar shape.[sic]
Another said: "That's a portal looks like something has arrived."
A third added: "Looks like the two divine hands prevented a dark portal from entering earth."
What do you reckon then - alien portal, or a load of b*llocks?