1941. The Clydebank Blitz robs Nessa Glover of her husband and five children. Struggling with her new reality she becomes a shipyard welder, and finds herself drawn into trade union activism. One day she visits Harmony, a commune built on notions of equality and unity, led by the charismatic Fergus Abercrombie. But not everything is quite as it seems at Harmony.

1980. Keir Connor is a traumatised war correspondent. When his father dies, he is left with a letter – a letter that takes him to Clydebank in search of answers. His journey leads him on to Harmony, now Laggandarroch, a residential school for disadvantaged children, as he tries to unlock the past. One thing is sure: Harmony is key.