Since 2017, UK terrorists have killed dozens and injured hundreds. But those atrocities – the ones on our evening news – are just the tip of a vast iceberg. Security services are striving to contain a staggering 3,000 potential threats from jihadists, far-right extremists and others. We are in a new age of terror, with decentralised, self-radicalising and hard-to-categorise individuals planning violence – but each one the British state catches can tell us something about our country.

Over five years, beginning with the Westminster Bridge attack, fourteen terrible plots have seen the light of day – but security and police forces have foiled more than twice as many. Some were thwarted by nerve-wracking undercover operations; others were narrowly avoided thanks to heroic citizens, or absurd mistakes by would-be attackers. Invariably, the all-too-human stories of these failed terrorists reveal the true picture of UK extremism.

Recounting interviews with senior counter-terror figures and astonishing court testimony, Plotters unpacks how and why British terror attacks happen – and don’t.

From dating apps and prison cells to Telegram networks and Tesco knives, Lizzie Dearden’s deep dive offers two disturbing certainties: the plotters will keep coming, and it’s only a matter of time before another one slips through the net.