After the tragic death of her husband, British housewife Rosemary Blake accepts a summer house and cat exchange across the Atlantic in her sister's adopted town of Edgemarsh Lake, New Hampshire. Lulled by promises of of beautiful scenery and a perfect day camp for her two children, she bids adieu to her gentle cat Esmond, and heads off to parts unknown.
But from the moment they arrive, Rosemary senses something amiss. Her sister Celia is skittish and secretive. Their temporary cat Errol, a oversized Maine coon, is out every night and clearly up to no good. Worst of all, a rash of deadly fires has the entire town sniffing for smoke.
Who is responsible for these lethal blazes? The fur flies as suspicions mount, and Rosemary realizes she must act quickly, before a fiery killer strikes again.