Johnnie (Li Hsui-hsien) is one of many voyagers seeking a mysterious monster in the jungles of India. Eventually, he comes across the enormous ape-like creature known as Utam. Shockingly, the beast is gentle and has a human companion, Samantha (Evelyne Kraft), whom he brought up after her parents' death. After Johnnie convinces Utam and Samantha to travel to Hong Kong with him, greedy promoter Lu Tiem (Ku Feng) exploits and mistreats the creature, causing Utam to unleash his fury on the city.