Given that we’re talking about endings, you should be made aware of the MASSIVE SPOILERS HERE.
SPOILERS ARE AFTER LUIS.
At one point, the film was going to end with a confrontation between Ant-Man and Martin Donovan’s shady villain Mitchell Carson. Donovan’s character deservedly gets his face slammed into a table by Hank Pym in the film’s prologue before going into business with Darren Cross.
During the Cross Industries heist, Carson makes away with the Cross particles for the Yellowjacket technology, and the original ending would have seen Scott Lang wrap up that loose end.
“At the end of the movie he gets away and has these Cross particles, and there was a sequence where Ant-Man has an encounter with him,” Reed told Cinema Blend. “But then for a couple reasons, it felt like maybe we should leave those particles out there. In that original thing, he took Martin Donovan out and got the particles.”
Carson definitely has some Hydra connections, and his escape could be setting something up further down the line. As great as Martin Donovan is, it’s hard to imagine anything topping the film’s final action sequence, though, so we’re glad that things shook out the way they did.