Tess is ten years old--old enough to join her mother, Sue, for a summer's fishing in the northern waters off Vancouver Island on their boat the Henry Bay. However Tess is reluctant to go: she fears the stormy waters and would rather stay at home for the summer with her best friend, Candice. Tess does go, and with her goes Maa-mou the cat, a parting gift from Candice, as her lively companion. Together they rise to the challenges of life on a fishing boat, and thrill in the summer's unexpected pleasures.