Spinning out of control! Now in paperback, the fifth and penultimate book in the internationally bestselling TUNNELS series -- with a teaser to TERMINAL, the end!

Just when you thought it couldn't get any deeper, darker, or weirder...

Creeping into the open through cracks in the earth, the Styx have surfaced, and are now infesting England like some parasitic scourge -- carriers of a bizarre black secret that will place every last Topsoiler in mortal peril.

Unless Will Burrows puts a stop to the propagation.

Armed to the teeth, with little more than a motley crew of former commandos as reinforcements, can Will, Chester, and Elliott find a way to squash the threat? Or will they only find themselves in a deadly downward SPIRAL?

Now in paperback, the fifth book in the internationally bestselling TUNNELS series. Includes a sneak peek at TERMINAL, the final book in the series!