In the fifth and penultimate book in the Tunnels series, The Styx have surfaced.

If you thought the Limiters were nasty, think again.

They've brought their females with them this time. And all that stands in their way are Will and his friends, and a rag-bag team of retired commandos.

It's a smoking spiral of chaos and not everyone is going to survive.

Highly-anticipated fifth book in the internationally bestselling Tunnels series.