The Tunnels adventure is far from over for Will Burrows. In his quest to find his father, Will is plunged even deeper underground. And as if things weren't bad enough already, he stumbles across a Styx plot with terrible implications for the world aboe. And a sister who isn't finished yet…

Fourteen-year-old Will Burrows lives with his family in London. He has little in common with them except for a passion for digging which he shares with his father. When his father suddenly disappears down an unknown tunnel, Will decides to investigate with his friend Chester. Soon they find themselves deep underground, where they unearth a dark and terrifying secret — a secret which may cost them their lives