Set almost entirely inside a hospital, where a neurosurgeon, a criminal patient and a police inspector are forced into a deadly stand-off, Hong Kong auteur Johnnie To’s action-thriller “Three” is executed with the precision and skill of brain surgery. Screenwriters Yau Nai-hoi, Lau Ho-leung and Mak Tin-shu ratchets up tension to suffocating levels by letting one touch-and-go situation trigger another, but most gripping of all are mental and moral meltdowns of protagonists under extreme duress. Compared with such stylistically on-the-nose works as “Exiled” and “Vengeance,” To’s craft here is nearly invisible, but action, timing, character chemistry and psychological intrigue are all synched to perfection. It’s first-rate entertainment that deserves a healthy life at festivals and on video platforms.

The Chinese title “Three People Walking” is lifted from Confucius’ “Analects”: “Among three people walking, there’s bound to be a teacher,” the kernel being, you can learn something from anyone. According to Yau, the film questions the maxim by demonstrating how those fixated on their own infallibility won’t learn their lesson. Although hubris has been the leitmotif in much of To’s oeuvre, the implications are a shade darker when the three protagonists’ vocations allow them to wield power over the life and death of others. Thus, the film boasts a socially conscious core reminiscent of “Life Without Principle.”

Although Hong Kong’s health care has traditionally been considered respectable by international standards, with the huge population it serves, aggravated by the influx of visiting mainland patients, there has been no shortage of medical scandals. Seen in this context, the figure of Dr. Tong Qian (Vicki Zhao), associate consultant in neurology, is both symbolic and topical. No sooner has she entered the ward than she is verbally mauled by a young man (Jonathan Wong) who has been paralyzed since she operated on him. She remains sullenly unrepentant, insisting that she took risks to give him a better chance of recovery.

More trouble brews when a police squad brings in a wounded criminal (Wallace Chung) for treatment. Although the patient has a bullet lodged in his head and has a six-hour window to operate, he’s as spry as a deer, mocking his nemesis Inspector Chen (Louis Koo) with erudite quotes from Hippocrates and Bertrand Russell, making one wonder why he’s robbing jewelry shops when he could probably get an academic tenure. With his accomplices at large threatening public security, both cops and robbers play dirty games right under the medical staff’s eyes.

Another operation develops complications, but Tong is still hellbent on doing things her way, even if it may cost the patient’s life. Her aggressive rage in reaction to well-meaning counseling by her supervisor Steven (Eddie Cheung Siu-fai, a wellspring of calmness and reason) mirrors Chen’s self-righteous conviction that he has to “break the law in order to enforce the law.” Completing this triptych of obsession is the criminal, who seems to enjoy outwitting the cops too much to care for his internal hemorrhages.

With a sense of the absurd, To contrasts the dour, stressed-out paramedics with some carefree, gleeful patients, like a nutty nerd (Timmy Hung) who treats his bed as an IT hub and an old man (Lo Hoi-pang, “Life Without Principle”) who’s lost his marbles and revels in pranks with disastrous consequences. And the ruses and reinforcements between Chen’s team and the criminals’ immaculately suited cohorts (a steely Michael Tse and suave Raymond Wong) are mapped out first with kooky humor, then with an air of rising peril, as in a scene set in a restroom that starts as droll slapstick but in the blink of an eye, erupts into unstoppable brutality.

The action comes less from shoot ’em ups than what happens on the operation table: Images of scalpels slicing into squirming flesh or blood squirting from ruptured veins are so graphic. it’s more gory and hair-raising than a gangster bloodbath. But there is also stunningly violent mayhem in store, and perhaps as a playful answer to John Woo’s “Hardboiled,” it builds up to a tour-de-force shoot out in which the cast manually simulates slow-motion, rather than using technology (a feat that apparently took three months to rehearse).

Always a formidable screen presence, Zhao convincingly merges the noble and principled side of Tong’s character with her high-strung personality. Her sheer terror at realizing that her attempt to save one person might lead to the death of many innocents is the film’s most provocative and humanely moving moment. While Tong’s identity as a mainland immigrant provides a sympathetic background to her continuous need to prove herself, neither Chen nor the criminal are furnished with any solid background or strong enough vendetta to justify their extreme decisions. Koo limns the inspector’s gallantry in having his team’s back with rugged heft, but less so his moral dilemma or self-doubt. Chung has a field-day as the prankish psycho, but is too cartoon-like to be taken seriously. The finale, though a feat of taut high-flying action, sports a deus ex machina that leaves one wondering if the protagonists’ transformations are too abrupt, and whether anyone’s really learned anything.

Tech credits again conform to To’s production shingle Milkyway Image’s slick, stylish standards, though there’s a noticeable strain for clean functionality. To’s anointed editor David Richardson eschews elaborate devices like flashbacks or multiple points-of-view to maintain a taut, racy linear narrative. D.p. Cheng Siu-keung’s camera moves around the crowded wards, antiseptic corridors and Stygian operation chambers with subtle verve, capturing their unique visual textures.

Film Review: ‘Three’

Reviewed at Shanghai Film Festival, June 16, 2016. Running time: <strong>88 MIN.</strong> (Original title: “Sam Yan Heng”)

  • Production: (Hong Kong-China) A Media Asia Distribution (Beijing) Co., iQiyi Motion Pictures (in China), Media Asia Film Distribution (in Hong Kong), Well Go USA (in North America, Australia, New Zealand, U.K.) release of a Media Asia Film Prod., iQiyi Motion Pictures Beijing Hairun Pictures Co., Impact Media Co., Beijing Baidu Netcom Science Technology Co., Shanghai Gewa Business Information Consulting Co., Shenzhen Film Studio Co., Wuxi Soulpower Culture Media Co., Media Asia Distribution (Beijing) Co., China Film Media Asia Audio Visual Distribution Co., presentation of a Milkyway Image production, in association with China Film Co-production. (International sales: Media Asia Film International, Hong Kong.) Produced by Johnnie To, Yau Nai-hoi. Executive producers, Peter Lam, Gong Yu. Co-executive producers, Liu Yanming, He Wei, Zeng Liang, Lin Ning, Yue Chuanjiang, Jason Jia, Jiang Defu.
  • Crew: Directed by Johnnie To. Screenplay, Yau Nai-hoi, Lau Ho-leung, Mak Tin-shu. Camera (color, widescreen, HD), Cheng Siu-keung; editor, David Richardson; music, Xavier Jamaux; production designer, Yu Ka-on; costume designer, Cheung Siu-hong; sound (Dolby Digital), re-recording mixer, Tu Duu-chi; visual effects supervisors, Ken Lo Wai-ho, Tommy Cheung Chin-wing, Edwin Choi, Marco Yip; visual effects, Different Digital Design, Polar Light; line producer, Elaine Chu; associate producers, Andy Lee, Kan Xiaoze, Liu Yong, Su Huijun, Liu Zhangbiao; casting, Tang Zhejun.
  • With: Vicki Zhao, Louis Koo, Wallace Chung, Lo Hoi-pang, Eddie Cheung Siu-fai, Lam Suet, Mimi Kung, Timmy Hung, Michael Tse Tin-wah, Raymond Wong, Jonathan Wong, Stephen Au Kam-tong, Cheung Kwok-keung, Tam Yuk-ying, Chu Kin-kwan. (Cantonese dialogue)