In 2019, a London teenager, Zac Brettler, fell to his death from a luxury apartment building on the banks of the Thames. On a desperate quest to understand how their son had died, his grieving parents made a terrible discovery: Zac had been leading a fantasy life, posing as the son of a wealthy Russian oligarch.

Patrick Radden Keefe follows Zac's parents on a dark journey to find out what brought him to the balcony that night - and how a teenager's life of make-believe drew him into the city's terrifying underworld.