It was 1966 and the times they were a-changing, even in the provincial New Zealand coastal town of New Plymouth. Skirts were getting shorter, the Vietnam War was on TV every night and French nuclear tests in the Pacific turned the night sky a violent red. Twelve-year-old Helen, the youngest daughter of an eccentric engineer and a musical theatre fanatic, was living in a crumbling castle overrun by nature, and overshadowed by the majestic Mount Taranaki. On the eve of puberty, everything suddenly is uncomfortable and unfamiliar to Helen. She feels lonely and lost, adrift in this new turbulent sea.

That is, until her father gifts her a tiger-striped kitten with extra toes on each paw. Noticing an M on the cat's forehead, Helen names her new companion Mickey. Inquisitive, clever and skittish, Mickey disrupts the already rambunctious household with his mischief. But as it turns out, he's just the ally Helen needs to explore the new world waking up around her.