Michael Fassbender on New Film Co-Starring Real-Life Girlfriend

The actor known for his serious roles opens up about his most dramatic film yet.

— -- Michael Fassbender has an impressive list of leading roles on his resume. From the antihero Magneto in Marvel's X-Men to the genius behind Apple as Steve Jobs, the Irish-German actor is well known for his emotionally intense performances.

Fassbender discussed his upcoming role in "The Light Between Oceans," with ABC News's Amy Robach. The film -- based on the best-selling novel by M.L. Stedman -- reveals a more passionate side than audiences have seen from him in the past.

The 39-year-old says the film is about "good people that have made bad decisions" and have to deal with the consequences.

Fassbender plays Tom, a former soldier who works as a lighthouse keeper.

"The war has damaged him pretty badly-- in so far as that he wants to isolate himself from all of civilization. So he gets this job as a light keeper," the actor told ABC.

Fassbender says he can relate to his character in that he spends a lot of hist off-screen time alone. "The nature of my job means that-- you know, many hours at home by myself," he said, admitting that he eats alone sometimes too.

"I'm the weird dude in the table by myself," Fassbender said laughing.

Tom falls in love early in the movie with Isabel, a beautiful and lively free spirit, played by his real-life girlfriend Alicia Vikander.

"She's such a fierce performer, she's so brave...she's not afraid to bring ugly personality traits to the forefront," Fassbender said.

The couple met on the set and Fassbender said they have "been seeing each other since."

Fassbender said this film is "an opportunity to appreciate how we all try and sort of navigate through life and do the best we can."

The actor said hopes people will walk away from the film and "give each other a hug."

"The Light Between Oceans" hits theaters nationwide on Sept. 2.