A young man sworn to an oath of non-violence works with his cousins in an ice factory where they mysteriously begin to disappear.

Courtesy of HKMDB:

Lo Wei began his film career in Shanghai during World War II and he achieved stardom soon after moving to Hong Kong in 1948. His first major supporting role was in the landmark epic Sorrows of the Forbidden City. Lo achieved leading man status with Prisoner of Love in 1951, and graduated to the director’s chair in 1953 with The Husband’s Diary, in which he also starred. He was one of the Shaw Brothers’ most prominent filmmakers between 1964 and 1970 with nearly twenty features as director-actor. He next moved to Golden Harvest where he directed Bruce Lee’s first two mega hits, The Big Boss and Fist of Fury. In 1974 he founded the Lo Wei Film Company and directed a half-dozen features with Jackie Chan between 1976 and 1979. Lo’s output slowed down in the 1980s, but he continued to be involved in motion picture production until his death in 1996.

Filmography:

• Dragon Fist (1979)
• Immortal Warriors (1979)
• Spiritual Kung Fu (1978)
• Magnificent Bodyguards (1978)
• To Kill with Intrigue (1977)
• The Kung Fu Kid (1977)
• Shaolin Wooden Men (1976)
• The Killer Meteors (1976)
• New Fist of Fury (1976)
• Shantung Man in Hong Kong (1975)
• The Girl with the Dexterous Touch (1975)
• The Bedevilled (1974)
• Yellow Faced Tiger (1974)
• Naughty! Naughty! (1974)
• Chinatown Capers (1974)
• The Tattooed Dragon (1973)
• None But the Brave (1973)
• Seaman No. 7 (1973)
• Back Alley Princess (1973)
• A Man Called Tiger (1973)
• Fist of Fury (1972)
• The Hurricane (1972)
• The Big Boss (1971)
• Vengeance of a Snowgirl (1971)
• The Comet Strikes (1971)
• The Shadow Whip (1971)
• The Invincible Eight (1971)
• Brothers Five (1970)
• The Golden Sword (1969)
• Raw Courage (1969)
• Dragon Swamp (1969)
• Red Line 7000 (1969)
• Death Valley (1968)
• The Angel Strikes Again (1968)
• Black Butterfly (1968)
• Forever and Ever (1968)
• Summons to Death (1967)
• Madam Slender Plum (1967)
• Angel with the Iron Fists (1967)
• The Golden Buddha (1966)
• Call of the Sea (1965)
• Crocodile River (1965)
• An Affair to Remember (1964)
• The Better Halves (1964)
• The Magic Lamp (1964)
• The Golden Arrow (1963)
• Song Without Words (1961)
• Meng Lisi, Maid of the Jungle (1961)
• Black Butterfly (1960)
• The Tender Trap of Espionage (1960)
• Tragic Melody (1960)
• Honeymoon Affair (1960)
• The Sweet Wild Flower (1959)
• The Golden Phoenix (1958)
• Jade-Green Lake (1958)
• How to Marry a Millionaire (1958)
• River of Romance (1957)
• A Wrong Move (1954)
• Blood-Stained Flowers (1954)
• A Woman of Throbbing Passions (1953)
• Mr. Handsome (1953)
• Diary of a Husband (1953)

Here is a curated selection of links for additional insight/information:

• Cultivate Cinema Circle info-sheet – link
• “In The Big Boss, Lee was Cheng Chao-an, a naive hick sent to labor at a Thailand ice factory with his fellow ethnic Chinese. The factory is a front for a heroin-trafficking operation. When his cousins discover this, they begin to disappear one by one. Sworn to nonviolence by his mother, Chao-an does not fight until he is provoked. The original director of The Big Boss, Wu Chia-hsiang, and fight choreographer Han Ying-chieh, a wuxia vet who also played the titular boss, wanted Lee to perform traditional stylized fight scenes influenced by Cantonese opera and kung fu. Lee preferred the efficient brutality of a street fight. The film’s action scenes ended up being more Han than Lee, with lots of big punches and high kicks. But Lee forced Wu out as director, and Raymond Chow brought in Lo Wei to replace him….On The Big Boss, Lee’s work was paradigm-setting. His wildcat scream at the ice factory heralds his first explosion of motion and blood. His tortured face and shaking body after his second fight there disclose anguish at the murders he has just committed. He would continue to refine and elaborate on these gestures. Chao-an’s final fight with the boss—with its stylistic clash of Lee’s and Han’s choreographies as subtext—set the stage for Lee’s rapid rise. The movie became the highest-grossing film in Hong Kong to that point.” — Jeff Chang, Criterion’s Current [2020] — link
• “Lee had spent most of the 1960s in American television, leaving behind Hollywood after a supporting role in 1969’s Marlowe. And with 1971’s kung-fu action film The Big Boss, directed by Lo Wei, Lee would revitalize his image and career with this runaway success. Lee is charming as Chinese immigrant who leaves behind his country existence to obtain a position alongside his cousin at a Thai ice factory. As soon as he arrives, his commitment to pacifism is immediately put to the test when there’s an altercation in which he must protect the virtues of a young woman accosted by a gang of miscreants, with his cousin arriving just in time to show Lee the ropes. Eventually, he discovers the ice factory is a front for a heroin ring, the owner using the ice to transport the drugs (as well as hide human bodies of factory workers who discover his secret). Efficiently paced, well-choreographed and full of entertaining moments featuring Lee, The Big Boss is the prototype for the template Lee would use over his next three features.” — Nicholas Bell, IONCINEMA [2020] — link
• “After the frustration of being relegated to a cartoonish supporting role in “The Green Hornet,” Bruce Lee returned to Hong Kong, surprised to find that he was an icon there. The HK film business realized they had something in Lee and tried to capitalize on it quickly as Raymond Chow and Golden Harvest signed the star to a two-picture deal. Even then, they weren’t sure Lee could carry a film, and so they started shooting his 1971 breakthrough, The Big Boss, unsure of who would be the film’s lead. The movie was set-up to go either way so that either Lee’s character or the one played by a bigger star at the moment, James Tien, would be killed halfway through, turning the movie over to a vengeance flick for the remaining actor. Lee won. Watching the movie a half-century later allows one to see one of the best examples of instant star status. The minute Lee comes on screen, he just owns it. There’s a confidence and swagger that’s like early Clint Eastwood, an actor that Lee wanted to emulate, and you can see how Lee’s work with Hollywood icons in L.A. like Steve McQueen and James Coburn taught him a thing or two about holding the camera’s gaze. Lee plays a Chinese man who moves to Thailand to work in an ice factory run by a drug smuggler. He essentially helps lead a worker revolution and avenge the death of his cousin, played by Tien. Some of the filmmaking is clunkier than Lee’s later films, but it’s still one of the more engaging martial arts films of its era, and one of those movies after which nothing would really be the same.” — Brian Tallerico, RogerEbert.com [2020] — link