Total Termination of the English: the Styx and their lethal cohorts of Armagi will settle for nothing less. Not even the mighty US military is prepared to stop the assault!

Will and Elliott are stranded underground, down in the innards of the Earth first mapped in DEEPER and FREEFALL. With the support of a small group of survivors from the plague of New Germania, they discover a startling secret at the site of the three core pyramids. A secret that may explain not only where the Styx came from, but the human race, too. Can Elliott, with her mixed blood, unlock the clues before the Styx and their Armagi swarm across the rest of the world, wiping out every single human being? And at what cost?

All the many threads of the prior TUNNELS books come together in this epic conclusion!