Only the Dead Live Forever — W.J. Lundy

The escape from Afghanistan was only the beginning. The Trio survived the initial fall, and built a refuge, they thought they had reached safety, but only to find themselves once again abandoned and surrounded by the primals. No contact with their families or commands, no relief from the rabid enemy. The fight continues as Brad and his men struggle to survive in a post-apocalyptic world where the enemy is far more dangerous than anything they had been trained for. Over Land Sea and Air they will do anything to reach home.