Today at least, for US Kindle (at least):
Ballistic by Paul Levine
http://www.amazon.com/BALLISTIC-ebook/dp/B004PGNQT2
This is a repeat freebie, so you might already have it.
From the Amazon description:
When a doomsday cult captures an U.S. Air Force missile base, it's up to a lowly sergeant and a female psychiatrist to prevent a nuclear holocaust.
Book page has a recommendation from Stephen J. Cannell summarizing the book as "'Die Hard' in a missile silo".
This is one of the few Levine books I haven't read yet (waiting for the time), but I've really enjoyed the 10 or so I have read, with most from the Solomon Vs. Lord or Lassiter series (and the Solomon vs. Lord series makes me do the baby-seal dance described by ATDrake when he writes a new one). Levine's been nominated for a wide range of big-time awards in the mystery field (I don't want to quote the wrong ones, and don't have time to look them up right now.) Levine writes characters with some depth, and typically possessing a sense of humor, so I would expect this book to follow suit despite it's "action" sounding description.
KentE