"For Whom the Bell Tolls." It's Sen. John McCain's favorite book, and it's now also the title of his much-anticipated HBO documentary.

HBO released the powerful trailer for "John McCain: For Whom the Bell Tolls" Thursday which opens with the Arizona Republican speaking directly to the camera.

"I've been tested on a number of occasions, I haven't always done the right thing. But you will never talk to anyone that is as fortunate as John McCain," he said with a smile.

The documentary is a poignant telling of the 81-year-old McCain's life from his days as a POW through his three decades of political service, going through the ups and downs and everything in between.

USA Today writes, "a series of extraordinary interviews with McCain, members of his family, Senate colleagues and former presidents paint a detailed, and at times raw, picture of the senator’s life."

Praise from Democrats is featured heavily in the film, according to USA Today, including interviews from Hilary Clinton, President Obama and Vice President Joe Biden.

McCain, who is battling an aggressive form of brain cancer, has been absent from Washington since late last year. On Thursday, his friends, family and colleagues gathered at the Capitol to watch the documentary.

One of McCain's closest friends, Sen. Lindsey Graham, said the movie told the Arizona senator's story "warts and all."

"John McCain: For Whom the Bell Tolls" premieres Monday, May 28 at 8 p.m. on HBO.

USA Today contributed to this report.