Two murders. An abandoned asylum. Will a mysterious former patient help untangle the dark truth? The body of an elderly woman has been found in the bowels of a derelict asylum on the banks of the Thames. As Detective Lew Kirby and his partner begin their investigation, another body is discovered in the river nearby. How are the two murders connected? Before long, the secrets of Blackwater Asylum begin to reveal themselves. There are rumours about underground bunkers and secret rooms, unspeakable psychological experimentation, and a dark force that haunts the ruins, trying to pull back in all those who attempt to escape. Urban explorer Connie Darke, whose sister died in a freak accident at the asylum, is determined to help Lew expose its grisly past. Meanwhile Lew discovers a devastating family secret that threatens to turn his life upside down. As his world crumbles around him, Lew must put the pieces of the puzzle together to keep the killer from striking again. Only an eccentric former patient really knows the truth—but will he reveal it to Lew before it’s too late?

Murder on an abandoned housing estate—and a web of dark secrets stretching back decades… Amid the crumbling decay of the Grasmere Estate in London, flats are abandoned and boarded up; the church that was once at its heart lies disused and forgotten. But when urban explorer Connie Darke takes refuge in the church while looking for clues about her sister’s death, she makes a terrifying discovery: William Stark, the estate’s architect and long-time resident, is hanging from the vaulted ceiling. For DI Lew Kirby, struggling with life-changing tragedies of his own, there’s no doubt that Stark was lured to his death—but who wanted him dead, and why? As Connie begins a covert investigation, desperate to find a connection to her sister, Kirby soon discovers that Grasmere’s remaining residents have something to hide. Could there be a connection between Stark’s death and the unsolved case of Kevin Shires, a boy who went missing from the estate decades ago? And with Kirby and Connie both digging into the long-buried history of the estate’s darkest corners, what other secrets will be unearthed from the ruins of Grasmere?