On a balmy L.A. night, Marlon Brando pulled his motorcycle into a rest stop and was surprised by three men with a gun who forced him into the back seat of a car.

They threatened to kill or castrate the actor, but ultimately released him unharmed. Carlo Fiore, a friend of Marlon’s, claimed the actor was “sure Sinatra was behind” the scare tactic.

The bad blood between Marlon and Frank Sinatra, costars in 1955’s Guys and Dolls, began a year before when Marlon won the part in On the Waterfront that Frank coveted.

“Sinatra felt that role was his,” explains James Kaplan, author of Sinatra: The Chairman, who says that Frank carried his hurt feelings to the set of Guys and Dolls. “It was really one-sided, with Frank detesting the ground that Brando walked on.”

Compounding their trouble was Marlon’s bad-boy image. “Sinatra came out of the glamour of Hollywood in the ’40s, while Brando was the new breed, who had open disdain for Hollywood,” explains Ben Mankiewicz, host of Turner Classic Movies, who notes that Frank began calling Marlon “Mumbles” on set. “I don’t think Brando came in hating Sinatra, but he grew to.”

Marlon could be a little devilish, too. During a scene where Frank’s Nathan Detroit eats cheesecake, Marlon kept blowing his line — forcing Frank to keep eating, take after take. “He definitely did it on purpose,” says Mankiewicz. “He was punishing Sinatra for his disruptive behavior.”

According to Brando Unzipped, a biography by Darwin Porter, the final straw came when Ava Gardner, Frank’s estranged wife, paid a visit to Marlon in his dressing room. “I feared Sinatra was going to order his goons to beat up Marlon,” said Fiore.

After his abduction, Marlon hired a bodyguard and gave Frank “a wide berth” until filming wrapped. Guys and Dolls became a hit movie, although its two costars never worked together again.