"After risking their lives as undercover anti-terror agents on the streets of Liverpool, Azo and Maya have fallen out of favour with their corrupt handler, Paterson. They used to hunt and kill on his orders - but now that they have found out the truth about what their spymaster really wants, Azo and Maya have become targets themselves. Off the grid, they take refuge in a web of ancient tunnels under Liverpool’s historic docklands, hiding from Hanzi, a child assassin whom Paterson has kidnapped and trained to hunt them."