Watch: 'Super/Man: The Christopher Reeve Story' explores how actor became real-life hero

Aug. 26 (UPI) -- Super/Man: The Christopher Reeve Story is a new documentary capturing the journey that saw Christopher Reeve go from a portraying a hero on the big screen to becoming one in real life.

Warner Bros. Pictures released a trailer for the film Monday.

Super/Man juxtaposes Reeve's acting career and his activism, examining his life before and after the 1995 accident that paralyzed him below the neck.

As the trailer opens , viewers hear Reeve say, "Everybody's looking for a hero. I am not a hero. That was a part, I played the part. I'm not that man."

Reeve's portrayal of Clark Kent and his Superman alter ego launched him to stardom.

The film includes interviews with Reeve's three children as they reflect on their memories of their father before the horseback riding incident.

"Doing things with my dad, it was all about activity and action," said Reeve's son, Matthew, in the trailer. "Riding bikes, playing soccer, skiing."

The directors, Ian Bonhôte and Peter Ettedgui, also incorporate family movies and footage from rehab.

"After becoming a quadriplegic, he became a charismatic leader and activist in the quest to find a cure for spinal cord injuries, as well as a passionate advocate for disability rights and care - all while continuing his career in cinema in front of and behind the camera and dedicating himself to his beloved family," an official synopsis reads.

As the trailer approaches its end, viewers once again hear Reeve's voice as he reconsiders his meaning of the the term, "hero," noting how his definition has changed.

He said that he used to apply the word to a person who acted courageously in the moment without regard for the future consequences.

"Now my definition is completely different," he said. "I think a hero is an ordinary individual who finds the strength to persevere and endure in spite of overwhelming obstacles."

The documentary, which initially screened at the Sundance Film Festival, premieres in theaters Sept. 21, and the movie will run through Sept. 25.