An asteroid brought about the destruction of the world…in a way no one thought possible.

After the death of her parents, Sloan Egan left their Montana ranch determined to make a difference in the world. Now a prominent surgeon with an exceptional career in her future, life has turned out exactly as she expected. Until a government summons arrives with an order to report to Fort Hood for a top-secret weekend retreat.

Major Lee Archer’s reassignment as head of military operations at The Bunker felt more like a prison sentence than a promotion. To make matters worse, he’s been assigned to babysitting detail, as a group of the country’s most brilliant young minds come together to test the vitality of the cutting-edge fallout shelter he commands.

But the retreat was nothing more than a ploy. One devised to safeguard the future of humanity, as a catastrophic event renders the world above uninhabitable.

Or so they’ve been led to believe.

Those in charge have a secret. One so horrifying they would do anything to keep it concealed. Because what lurks beyond The Bunker is deadlier than anyone could have ever imagined.

And it’s only a matter of time before it finds a way in.