Its plot follows a trio of extraterrestrials, one of whom has the form of a cat, who team up with a novelist named Wisely to fight a malevolent alien that can possess humans.

Tung enters the neighbor's now-empty apartment, where he sees piles of newspaper on the floor, some of them bloodied.

Inside, Wisely overhears the girl telling the cat that they must find a second octagon in order to defeat "the star killer" and return home.

Upon visiting the crime scene, Wisely sees that the area is covered in scorch marks, and finds cat hair.

At a hospital, Chen takes Lao Pu home, and Wisely learns from a bone analysis that the cat the tail belonged to died many years prior.

The cat, whom the alien girl calls "the General", enters Wisely and Pai So's home, wanting his tail back.

Her distant home sends a beam of light down to the observatory, radiating the General's body and making him "the strongest knight in the universe".

Author John Charles, in his 2000 book The Hong Kong Filmography, 1977–1997, gave The Cat a score of nine out of ten stars.