"Captain America: Civil War" actor Sebastian Stan talks about The Winter Soldier's past.

During a press tour for "The Martian," the 33-year-old revealed that The Winter Soldier's back story will be revealed in "Captain America: Civil War."

"Where we find him after 'Winter Soldier,' he's in a place where he is learning about himself, and he's discovering - as you saw in the last scene of 'The Winter Soldier,' at the museum - he's starting to put the pieces together, starting to learn about the past," Stan said in a statement published by Screen Rant. "Where he's been. What he's done. And as you'll see in the next movie, it doesn't come without a huge price: emotionally, mentally and... yeah, it's not easy for him to learn about what he's done."

Stan reveals that though Hydra has tortured him and erased his memory several times, the now defunct evil organization is the reason The Winter Soldier is still alive in "Captain America: Civil War."

"You have to remember it is the same Hydra in a sense that is responsible for him still being alive," he said. "And what happened before the movie 'Winter Soldier' - and there will be a lot of things sort of made more clear in 'Civil War' about what happened with him - kind of set up this relationship that he may always have with Hydra, one way or another.

"Because in a way they are like his second family. If that makes sense."

Along with Stan, "Captain America: Civil War" also stars Chris Evans as Captain America, Robert Downey Jr. as Iron Man, Scarlett Johansson as Black Widow, Jeremy Renner as Hawkeye, Anthony Mackie as Falcon, Paul Rudd as Ant-Man, Chadwick Boseman as Black Panther, Elizabeth Olsen as Scarlet Witch, Don Cheadle as War Machine, Emily VanCamp as Agent Sharon Carter, Paul Bettany as Vision, Frank Grillo as Crossbones and William Hurt as General "Thunderbolt" Ross.

The movie releases in theaters on May 6, 2016.