Based on a true story, the film “The Stanford Prison Experiment” shows what happens when a college psychology experiment goes wrong. Opening July 31, it is one of three films showing through Aug. 6 at UNL’s Mary Riepma Ross Media Arts Center.

Also showing are “Testament of Youth” and “Mr. Holmes.”

“The Stanford Prison Experiment” features Billy Crudup as Philip Zimbardo, a Stanford University professor who cast 24 student volunteers as prisoners and guards in a simulated jail. The study, completed in 1971, was designed to examine the source of abusive behavior in the prison system.

Results of the study were astonishing as, within just a few days, participants went from middle-class undergraduates to drunk-with-power sadists and submissive victims.

The film, created with the help of Zimbardo, won two awards at the Sundance Film Festival, including best screenplay.

Along with Crudup, the film features a cast of rising young actors, including Ezra Miller, Olivia Thirlby, Tye Sheriday, Keir Gilchrist, Michael Angarano and Thomas Mann.

“The Stanford Prison Experiment” is rated R.

“Testament of Youth” is a powerful story of love, war and remembrance, based on the World War I memoir by Vera Brittain, which has become the classic testimony of that war from a woman’s point of view. A searing journey from youthful hopes and dreams to the edge of despair and back again, it’s a film about young love, the futility of war and how to make sense of the darkest times. The film is rated PG-13.

“Mr. Holmes” is a new twist on the world’s most famous detective. In 1947, an aging Sherlock Holmes (Ian McKellan) returns from a journey to Japan, where, in search of a rare plant with powerful restorative qualities, he has witnessed the devastation of nuclear warfare. Now, in his remote seaside farmhouse, Holmes faces the end of his days tending to his bees, with only the company of his housekeeper and her young son, Roger. Grappling with the diminishing powers of his mind, Holmes comes to rely upon the boy as he revisits the circumstances of the unsolved case that forced him into retirement, and searches for answers to the mysteries of life and love – before it’s too late. The film is rated PG-13.

For more information, including show times, go to http://www.theross.org or call 402-472-5353.