Star Wars: The Force Awakens actress Daisy Ridley has seen some wildly hairy faces in her short film career (we're looking at you, Chewbacca).

But nothing could prepare Ridley for her first look at Kenneth Branagh as famed detective Hercule Poirot on the set of Murder on the Orient Express. Or more specifically, for the sight of Poirot's audacious mustache.

"Daisy looked at me and said, 'My God. That’s bold!' " Branagh recalls. "I asked in a slightly smaller voice, 'Bold good?' And she went, 'Bold great!' So I'm buying bold great. Daisy knows whereof she speaks."

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It's not just Ridley. Branagh's audacious Poirot mustache is a certified hirsute standout in the screen adaptation of Agatha Christie's murder mystery (now in theaters). It rides first class on the opulent train, along with a stellar cast that also includes director Branagh, Johnny Depp, Judi Dench and Penélope Cruz.

Branagh says the facial hair for the brilliant, flamboyant detective was crucial, especially to Christie's family, who served as advisers on the film.

"The first thing they asked in their creative meeting was, ‘What are you doing about the mustache?' There was no twinkle in the eye," says Branagh. "I knew it was critical. This mustache is serious business."

Christie, who died in 1976, was highly protective of her famed Poirot and his prized mustache, which she described in her works as "magnificent" and "immense."

"This mustache is like Poirot's superpower, his calling card," says Branagh. "It’s what people see before they see him."

Branagh heard that Christie's husband, Max Mallowan, had a (gasp!) facial hair quibble with Albert Finney's Poirot in Sidney Lumet's 1974 film version of Orient Express.

"They loved the 1974 version," says Branagh. "But her husband said, 'The mustache. That’s too small. That doesn’t constitute the most magnificent mustache in England.' We knew in this case, size was going to matter."

Hair and makeup designer Carol Hemming spent months researching great mustaches of history before finding a picture of a proud 19th-century cavalry officer with, in Branagh's words, "this kind of massive, double-barrel handlebar."

Branagh tried to grow it himself ("I depressingly realized I'm follicly and hormonally challenged") before Hemming created the hair opus. There were several, featuring Branagh's own hair combined with heavy cashmere for the cold, wet English shoot.

"The damp brings the terrible specter of droop to the flourishing mustache," he says. "With this much upward sweep, that's a disaster."

He would spend an hour having the hair applied before walking to the set past four busts of himself featuring "this agitated, kind of coyote mustache crawling across them" ready to go. "That sight was slightly alarming."

Branagh consumed his food through a straw while in costume ("That mustache is the enemy of elegant eating") but admits to fateful bouts of "mustache-cocky" eating behavior.

"My biggest disaster was a bowl of muesli with honey that entangled itself in the top lip," says Branagh. "I’m afraid it was all hands on deck. Code red. Mustache one off, mustache two on."

Headaches aside, Poirot's mustache is a hit, serving as a fearless tie-in with the Movember Foundation's annual mustache-growing fundraiser. James Prichard, Christie's great-grandson and a producer, calls it "extraordinary."

"I think Ken has got the greatest mustache of all England," says Prichard.