Hope's mum died over a year ago and she misses her terribly. Her twin elder sisters have each other, and her dad has just started dating again, but Hope is lonely. A growing interest in the environment becomes an out-of-control obsession as Hope tries to find solace and meaning in her life, driving her family mad in the process.

First, she tries to turn them all vegan, and then suggests limiting shower time and selling the family car to walk everywhere. The more fed up her family get, the more misunderstood Hope feels, until she finally decides to run away and find the only person, she is sure will understand her: Greta Thunberg! Hope's family need to convince her that she is loved and valued - but can they find her in time?