Alex and his friend Rocky are upset by the recent burglaries in their housing development. Pete, Alex's cat-who can understand perfect English but cannot speak-awakens Alex to see a suspicious vehicle leave the house next door. The new neighbors discover that they, too, have been burglarized.

Alex's little brother, Benjie, worries that the burglars will return to kidnap Pete. His fears come true when he discovers burglars at his house and Pete in the thieves' van. Benjie confronts the thugs, who throw Pete out but kidnap Benjie. Benjie must use his wits to escape, while Pete bravely ignores his own injuries to help Alex save his brother.

Told partly in Pete's voice, Spy Cat is a page-turning adventure about the importance of family and friends.