The Conways, celebrating Kay's 21st birthday in 1919, seem a golden family - safe and well after the Great War, looking forward to future careers, marriages, and a brave new world. Through J B Priestley's masterly manipulation of time, we see into their future and back again to where the seeds of their downfall were planted.

There's a great devil in the universe, and we call it Time.

Priestley was fascinated by the study of time. Writing in 1937, he saw how Britain was complacently failing to learn from history and charging headlong towards another conflagration.

Time doesn't destroy anything. It merely moves us on - in this life - from one peep-hole to the next.

The NT returns to Priestley for the first time since its ground-breaking production of An Inspector Calls.