London during a blistering heatwave. A man wakes in the middle of the night, hearing noises from downstairs. He assumes it's a burglar - nothing prepares him for what he finds.
Across the city, DI Leah Hutch and DS Benjamin Randle are called to a murder scene outside their jurisdiction. A woman has been killed - the only suspect, a friend from Leah's past who refuses to speak to anyone but her.
Meanwhile, fourteen-year-old Zed Okoro's mother has vanished. He will do anything in his power to find her - even if it means risking his own life.
As Leah and Randle investigate, they discover a conspiracy with roots far from home.
Three incidents. One connection. What secrets make people kill?