"The Remaining: Extinction (The Remaining, 6)" by D. J. Molles

"The Remaining: Extinction (The Remaining, 6)" by D. J. Molles
  https://www.amazon.com/Remaining-Extinction-D-Molles-author/dp/0356505901/
Book number six of a six book apocalyptic science fiction series.  There is another series in the same universe with the main character for a total of eighteen books.  I read the well printed and well bound trade paperback published by Orbit in 2015 that I purchased new in 2025 from Amazon.   I have the first book in the second series and will read it soon.
Captain Lee Harden of the US Army is a member of the US Special Forces. His duty is to live in his remote US Army built home with a steel and lead concrete bunker underneath it.  Any time the US government gets nervous, he goes down into his bunker with his dog and locks the vault door.  He then talks with his supervisor daily over the internet until released by his supervisor to leave the bunker.  His duty is to stay in the bunker during any event and come out thirty days after he has zero contact with his supervisor.  Then it is his duty to find groups of people to restore order in his portion of the USA.
Then one day, Captain Harden has been sitting in his bunker for a couple of weeks and his supervisor does not call.  A plague has been sweeping the planet and things are getting more dire by the day.  Apparently the infected do not die but their brains are mostly wiped out.  Zombies.  A month later, Captain Harden and his dog emerge from their bunker to find a total disaster with infected roaming the countryside.
Captain Harden’s home and bunker were burned out after everything to eat or shoot was stolen by a gang of bad guys.  But he has a secret, he has ten bunkers built by the U.S. Army strategically located around the state.  And only he can open the bunkers.  But the bad guys are chasing Captain Harden to get the rest of the food and ammo from him.  And
nobody trusts anybody.
The Marines from Camp Legume have shown up and allied themselves with Captain Harden.  The Delta Force from Fort Bragg have also shown up an allied themselves with Captain Harden.  But, millions of infected crossed the river into North Carolina before the bridges were blown up.
The author has a website at:
    https://djmolles.com/blog/the-remaining-universe-reading-order
My rating: 4.5 out of 5 stars
Amazon rating: 4.7 out of 5 stars (3,052 reviews)
Lynn