Nobody noticed it, but the funniest thing happened when Hugo Chavez visited Britain in 2006. At the Camden Centre, a large art deco town hall in Central London near the British Library, the event hosted by then London mayor Ken Livingstone was packed out with young people, suddenly more curious and more left leaning thanks to the political mistakes of a now waning New Labour government. Was an alliance forming? Tony Benn watched Jeremy Corbyn and Diane Abbott greeting the Venezuelan premier. “It’s an extraordinary story really,” wrote Benn in his diary that night — now the best-selling sounding board of a cozy national treasure — “he’s very imaginative, is old Ken.”

The kids were feeling it. The old guard was feeling it. Even Sir Ian Blair — the head of the Metropolitan Police — was feeling it, defying his namesake prime minister to provide a police escort for Chavez on Livingstone’s urging. Off the radar of most of the media, a new coalition was forming that would take a decade to reveal its huge implications. The Searchers, the fourth book by Guardian journalist Andy Beckett and first for nearly a decade, is a group biography of how “five heretics” — that is, Tony Benn, and then Diane Abbott, Jeremy Corbyn, Ken Livingstone, and John McDonnell — came out of the politics of the 1970s to upend the politics of the 2010s. All four surviving heretics spoke to Beckett for the project.

Andy Beckett is interested in the what-if moments in modern British capitalism, even if its temporary vulnerabilities only ever reveal its strengths. The Searchers is in many ways the harmonizing of tunes from Beckett’s previous works. Pinochet in Piccadilly, published in 2002, used the then recent arrest of General Augusto Pinochet at the London Bridge Hospital to measure British (and specifically Thatcherite) complicity in the dictatorship that followed Pinochet’s coup against Chile’s democratically elected Popular Unity government and the murder of President Salvador Allende.