"I'm innocent!" screams young kung fu student Ti Yuen (Ng Yuen-Jun) as jailers drag him off to share a cell with shaggy-haired long-term convict Ting Dien (Jason Pai Pao). Wrongfully accused of raping his sister-in-law, Yuen figures out he is the hapless pawn in a scheme hatched by his evil seniors Man Kwai (Dick Wei) and Man Niang Sang (Kwan Fung) together with the no-good Master Qui Cheung Fat (Tong Kam-Tong). It is their intention that Ti Yuen befriends Ting Dien so the latter will share his 'Deadly Secret' so they can extract that information later. Every day Ting Dien endures horrific tortures concocted by corrupt magistrate Ling Tui Si (Yueh Hua). Tui Si also wants the Deadly Secret but the near-superhuman Ting Dien won't crack. One night Ti Yuen hangs himself in despair but Ting uses his mystical martial arts powers to revive him. Taking pity on the youth, Ting Dien trains him in the arcane art of San Chiu kung fu and shares the sorry tale of how he came to learn the secret seemingly every kung fu killer is after.
A Deadly Secret spins one of the more intricate plots for a Shaw Brothers kung fu film. Rife with ambiguity and intrigue the unorthodox narrative opts for an answers first, questions later style of storytelling that serves the central mystery very well. It was written by the staggeringly prolific Ni Kuang, of whom it is easier to list the Shaw Brothers films he did not script than those he did. Even more interesting, A Deadly Secret was an early effort from one of the most controversial filmmakers in Hong Kong cinema: T.F. Mou Tun-Fei. His claim to infamy came later with Men Behind the Sun (1988), a gross-out shocker depicting real-life atrocities committed by the Japanese military on both Chinese prisoners of war and civilians during the Second World War. This bad taste epic went on to become Hong Kong's equivalent of a video nasty and yet Mou Tun-Fei's early works in his native Taiwan included anti-Communist propaganda and dramas inspired by Italian neo-realism.
On joining the Shaw stable Mou Tun-Fei delivered Melody of Love (1977) a sweet romance starring a young Danny Lee then co-directed horror anthology Haunted Tales (1980) with the great Chu Yuan and true crime shocker Criminals 5 – The Teenager's Nightmare (1977) with horror and crime specialist Kuei Chi-Hung. But his most notable work for Shaw Brothers would be Lost Souls (1980), a brutal and sadistic account of illegal immigrants held captive and sexually and physically abused at the hands of human traffickers. Compared by some to Pier Paolo Pasolini's Salo, or 120 Days of Sodom (1975), opinion remains divided as to whether the film is a searing indictment of social injustice or merely a brazen and vile exploitation epic. Either way it set the tone for Mou Tun-Fei's subsequent output. Following the financial success of Men Behind the Sun he struck back with the conceptual sequel Black Sun: The Nanking Massacre (1995). He also dabbled in hardcore pornography with Trilogy of Lust (1995) though in the wake of his controversial reputation has yet to secure funding for third film in his war crime trilogy.
Mou Tun-Fei's propensity for melding social satire with brutal torture scenes is rendered somewhat more palatable here within the context of a labyrinthine wu xia morality play. Whereas someone like Chu Yuan revels in the game play and mystery in his outlandish swordplay fantasies, Mou Tun-Fei utilizes the form to expose the cruelty, hypocrisy and self-interest he, somewhat cynically, perceives in society at large. As such A Deadly Secret fits neatly into the brief cycle of darker, angrier Shaw kung fu films from the Eighties that took a more jaded look at conceits like chivalry, brotherhood and filial loyalty within the Martial World: e.g. Eight Diagram Pole Fighter (1984) and Usurpers of Emperor's Power (1984). Judging from his filmography Jason Pai Pao was that rare kung fu star that relished an acting challenge. In A Deadly Secret he gets to sport crazy hair, brood mysteriously, endure brutal torture, rant like a loon and kick all sorts of ass. In a neat conceit the most notorious criminals in China confess their crimes just so they can be locked up with Ting Dien and force him to share the Deadly Secret. Naturally he proves less than cooperative as trick photography lends Pai Pao's invincible martial arts moves the proper mystical air. Away from his crazy old kung fu master makeup, he also gets to play the dashing romantic lead in flashbacks. Ting Dien's love interest is none other than Ling Tui Si's saintly daughter Seung Wa, the one person to whom he would consider revealing his secret though, rather sweetly, she never asks. Seung Wa is played by Shih Szu who only a few years prior was among the studio's top box office draws. It is a trifle disheartening to see the former queen of kung fu reduced to a meek and much-abused love interest. Only a few years later she left the studio to round off her career in low-budget fantasies like Chinese Magic (1983). Nevertheless, evidently drawing on his previous romantic dramas, Mou Tun-Fei paints a surprisingly affecting, impassioned story of tragic love. Though the frenzied finale treads close to bleak-humoured farce it resolves the mystery in spectacular fashion.