Director: Zhang Yimou
Cast: Christian Bale, Ni Ni, Huang Tianyuan, Zhang Xinyi
Certificate: 18

"I am not a priest!" That’s Christian Bale as John, a mortician who finds himself in Nanking in 1937. One hour later and he’s standing in a church, wearing a dog collar, and shouting: "This is the house of the Lord! I am the priest!"

It’s the first of many lies in Zhang Yimou’s unflinching war epic. Inspired by accounts of Americans trying to help shield the Chinese from Japan’s infamous Rape of Nanking (a six-week period of occupation in which soldiers brutally raped and slaughtered civilians), it sees John wind up in an abandoned church surrounded by young orphans. The invading troops soon take an interest in the virginal group. Faced with the assault first-hand, he tries to help. "Everything’s going to be fine," he tells them. That’s another lie.

Why should they trust him? There’s no reason to. He’s an alcoholic, a foreigner and he’s certainly not a priest. Plus he has a beard. But his gruff, selfish exterior inevitably gives way to a soft, soppy heart. He even has a shave. Then, suddenly, he’s a hero to root for. He helps the children get food, tries to plan an escape, and lets a gang of prostitutes shelter in the church with them. Oh, and he starts to woo their leader, Yu Mo (Ni).

It’s the kind of transformation that defines these stereotypical dramas about reluctant heroes – the only thing more clichéd than bringing in a white American to explain another country’s history. But while The Flowers of War is guilty of these, Yimou has a trick up his sleeve: he’s really good at both of them.

After his forced remake of the Coen Brothers’ Blood Simple, it’s a relief to see the director back in familiar, stunning territory. Handheld cameras appear during tense moments of fear among the kids, while graceful zooms and lighting bring out the delicate beauty of the location. Even the action, which is few and far between, is nail-biting stuff as we watch one crafty sniper try to take out an entire platoon of soldiers on a dilapidated building site.

Inevitably, other familiar tropes rear their heads - an enemy officer who isn't like the rest because he enjoys classical music - but Heng Liu's script turns them into catalysts for yet more grisly terror. And, thanks to stellar performances from the un-manly Huang Tianyuan as Bale's young sidekick and Ni's seductive female, that horror really hits home.

But never more so than when Christian Bale is on screen. You may not buy into Yimou's ambitious dream of a Chinese-Western co-production, but Bale is on electric form as the American lead - it's impossible not to be moved as he fibs to the kids to keep them happy. You could change the film's title to "Christian Bale Lies to Children for Two Hours" and you would still well up.

Aside from its clichéd concept, The Flowers of War doesn't put a foot wrong. It's a beautiful, harrowing historical drama that leaves you peeking at the brutality of war through a stained glass window. And if anyone tells you they didn't cry during the final act? They're lying too.