Mankind is no longer at the top of the food chain.
The Sixth Extinction is an apocalyptic tale about a pandemic that sweeps the globe, decimating the human race, leaving humanity struggling to survive. Within three weeks, everything has changed. Social structure has collapsed as the government locks itself away with a select portion of its vast army in deep bunkers, leaving the civilians to their own fate and the infected that stalk the streets.
Alex, Troy, Frank, Naomi and the two King brothers have joined forces with Smokie and her ragtag group of survivors. They have made their way onto a huge container ship anchored in a cove. They just managed to survive an attack, and are still reeling from losing the Shapter sisters and a few others on the shoreline. They now reside inside an impenetrable floating metal fortress an artificial island. What could possibly hurt them now? Within hours of arriving the vast ship is rammed by a boat. Then as they try to make sense of the unfolding events, another ship hails them. It is the well-armed, coastguard vessel, the Hamilton. The problem is it has been commandeered by a misfit crew of people willing to hunt on the weak. As if it's not bad enough having to defend themselves against the creatures that stalk the land, now they have to prepare to defend themselves against other humans willing to target anyone who manages to survive.
During the attack the priest Frank starts to lose his beliefs. While at the same time Troy has a dark spiritual awakening.
Meanwhile, Doctor Bachman and Emma have teamed up with Ralph, a person with the knowledge needed to destroy the creatures as they tried to exit the underground bunker. They managed to fry the horde just in time. However, just as they succeeded, the doors to their room burst open and something rushes in.
All that remains of the amass horde is a mere inch of wiggling tentacle that managed to drop onto the dusty ground outside before the door slammed shut, which was then scooped up by a passing crow.
Also, what does Stu think he will accomplish, as he steals a boat and rushes to the aid of his infected daughter?
And who is the stranger, secreted in the bowels of the massive container ship? While the group is still reeling from the attack of the coastguard vessel, one of them is captured by the stranger and dragged down into the belly of the ship.