During the panel, they were asked about what was coming in the next Captain America film. In response, Mackie gave his own personal plot synopsis for the film.
"Cap and Falcon go looking for Winter Soldier," he said. "They find him. They go through this traumatic ordeal of him transforming back into Bucky. Then, once he goes back to Bucky and we get all the craziness out of his head, then we become a three-man duo – he's got a shield, he's got an arm, and he's got wings - and we go out, and we save the world. Cue theme song. And then we go beat up Batman and Superman."
That last bit is playing off of the rivalry – perceived or otherwise – between the films Captain America 3 and Batman v. Superman: Dawn of Justice, which Mackie has a history of fanning the flames of since the two formerly shared a released date.
Captain America 3 comes to theaters May 6, 2016.