The laws to protect them were laid down by the Founders and are enforced by the all-powerful, not to say Stasi-like, judicial department. Under their law, once said these words cannot be undone and the speaker is condemned to life outside and, it is assumed from the blasted-heath view from every screen beaming images back from the surface to the people, certain death.

We first meet Sheriff Becker (David Oyelowo), the man in charge – along with mayor Ruth (Geraldine James) – of overseeing the peace and stability of the silo, as he announces his desire to go outside. The story is equally thrilling and, as the plot thickens with almost every scene and does not stop even at the very last moment (a second series has already been commissioned, as well it should), equally oppressive. It’s Soviet architecture meets steampunk medieval and the rendering of the silo’s different sections, from hydroponic farms to medical centres, make the place almost a character in its own right. The set designers and CGI wizards have had a field day crafting an environment whose futuristic bones are now only just visible beneath shrouds of grime and the kind of Heath Robinsonesque clutter that is bound to accumulate in a sealed human vault over time. No one knows when this will be, just as they don’t know who built the silo, since a rebellion in the past erased their history. The last few thousand people left alive on Earth at some unspecified (but we suspect not too distant) time in the future have been confined in a multilevel, self-sustaining, subterranean silo while they wait for the planet to recover from whatever toxic event rendered it uninhabitable. The world-building is meticulous, and that world is almost entirely underground. S ilo, Apple TV+’s 10-part adaptation of the first book in Hugh Howey’s bestselling trilogy of the same name, is not for the claustrophobic.

Howey silos