To fully grasp writer, director, editor, and cinematographer Cheng Er’s new period espionage thriller “Hidden Blade” requires at least a working knowledge of the complicated politics of China during World War II (certainly more than I have). His film is built upon a dense and layered story that’s deeply rooted in history and laced with pinches of propaganda. That may sound daunting, but Er’s gifts as a filmmaker and storyteller makes it worth the effort.

Adding to the challenge is Er’s choice to hop back and forth across his timeline. It’s an artistic stretch that can seem frustrating at first, but that ultimately comes together in some pretty clever ways. Er flashes back to 1937 during the bombings of Guangzhou, hops ahead to December 8, 1941 – the day after Japan attacked Pearl Harbor, and spends most of his time in Shanghai in the days leading up to Japan’s surrender to the Allies on September 2, 1945. There’s quite a bit of time-hopping and it can be disorienting, at least until you get a sense for what Er is doing.

A strong cast fills out this engrossing story about a select group of Chinese counter espionage agents in Shanghai tasked by the puppet Wang Jingwei regime to root out, interrogate, and terminate fellow countrymen who are secretly working to undermine the Japanese occupation. But covertly working within the group’s ranks were members of the Chinese Communist Party’s underground. These double-agents risked their lives secretly gathering vital intelligence that helped build a stronger and more unified resistance.

A brilliantly understated Tony Leung plays Mr. He (Leung), the director of the counter espionage unit working directly under a Japanese officer (a really good Hiroyuki Mori). Other key members of the group are Mr. Ye (Wang Yibo) and Mr. Tang (Da Peng). Both are stern and business-like agents who do everything from rounding up suspects, to overseeing (often brutal) interrogations, to executing prime targets.

Yet all of the key players remain a puzzle. Knowing that this is a spy thriller, we venture into it with our antennas up, looking for clues as to where each person’s loyalty may lie. But Er does an excellent job keeping allegiances and motivations under wraps, revealing them at just the right time and with just the impact they need.

As we begin to get a clearer picture of who’s who, we’re treated to some riveting confrontations. Some are impeccably written and performed one-on-one conversations where characters seek to prove or disprove their suspicions. Some burst out into full-on violence. Chases, shoot-outs, and one especially exhilarating fight scene are handsomely staged and shot. Just to be clear, “Hidden Blade” is far from an action-heavy movie. But the action we get is first-rate and comes at crucial points in the story.

As for the overall look of the film, Er gives us one stunning shot after another. The framing, the blocking, the lighting – it all adds to the immersion and shows off a pretty clear noir influence. And while he shoots action exceptionally well, I also love the way Er shoots his characters. Through his camera he’s able to pull so much from his actors, often without them uttering a word. The visuals turn out to be a crucial part of Er’s storytelling. That may sound obvious since most filmmakers consider it important. But here there’s a special emphasis that really enhances the experience.

Sadly Zhou Xun, Jiang Shuying, and Zhang Jingyi aren’t left with much to do in the film’s three female roles. They each give sublime performances that left me wishing the movie had gone deeper into their characters. And again, putting all the pieces of the story together can be more challenging than it needs to be (truthfully, the nonlinear structure doesn’t seem necessary, and I can see it being a frustration for some). But if you toss those two issues aside, it’s hard to find much wrong with “Hidden Blade”. It’s absorbing cinema. And even with its not-so-hidden nationalistic bend, its a beguiling spy thriller with a stylishly sumptuous genre veneer.

VERDICT – 4 STARS