Marvel fans immediately went into overdrive trying to figure out what it meant.

In the previous film, Infinity War, half of the superheroes died, so one fan theory about the light was that one more hero is going to die. And since Chris Evans recently confirmed he was done playing Captain America, sights were set on him.

Of course, it could just be the brothers messing with fans and a picture of a set light.

Either way, fans are going to have to wait some time to find out. Before the pic is released, Brie Larson's Captain Marvel will hit theaters March 8, with Avengers 4 is set to open May 3.