In the last days of the twenty-first century, sea creatures swim through the ruins of London. Trapped in the abyss, humankind wavers between fear and hope—fear of what lurks in the depths around them, and hope that they might one day find a way back to the surface. When sixteen-year-old submersible racer Leyla McQueen is chosen to participate in the prestigious annual marathon, she sees an opportunity to save her father, who has been arrested on false charges. The Prime Minister promises the champion whatever their heart desires. But the race takes an unexpected turn, forcing Leyla to make an impossible choice. Now she must brave unfathomable waters and defy a corrupt government determined to keep its secrets, all the while dealing with a guarded, hotheaded companion she never asked for in the first place. If Leyla fails to discover the truths at the heart of her world, or falls prey to her own fears, she risks capture—or worse. And her father will be lost to her forever.

The sequel to London Shah’s thrilling futuristic mystery The Light at the Bottom of the World, perfect for fans of Illuminae and These Broken Stars Leyla McQueen has finally reunited with her father after breaking him out of Broadmoor, the illegal government prison—but his freedom comes at a terrible cost. As Leyla celebrates his return, she must grapple with the pain of losing Ari. Now separated from the boy who has her heart and labeled the nation’s number one enemy, Leyla must risk illegal travel through unchartered waters in her quest for the truth behind her father's arrest. Across Britain, the fallout from Leyla's actions has escalated tensions between Anthropoid and non-Anthropoid communities, bringing them to an all-time high. And, as Leyla and her friends fight to uncover the startling truths about their world, she discovers her own shocking past—and the horrifying secrets behind her father’s abduction and arrest. But as these long-buried truths finally begin to surface, so, too, do the authorities’ terrible future plans. And if the ever-pervasive fear prevents the people from taking a stand now, the abyss could stay in the dark forever.