Most people have to wait until they're seventeen to enlist in the military but due to the zombie apocalypse Faith and Sophia Smith find themselves officers at ages 13 and 15. As the Wolf Squadron fleet begins searching for the resources necessary to manufacture a vaccine for the zombie virus, both sisters discover that there is more to being an officer than shooting things. With an assault on Guantanamo Bay in the works and a mission that's literally from out of this world, it's time to move past the sibling rivalry and learn to work together. After two books of Smith vs Zombie mayhem, Ringo keeps the formula fresh by dividing the focus more evenly between Faith and Sophia and pushing the characters out of their comfort zones.

Until now Faith has gotten by as a marine by being the best zombie killer in the fleet. But after displaying childish behavior in the middle of a firefight her father decides it's time she start being accountable as an officer in the marines with real responsibilities. Sophia's command is also expanded and she finds herself responsible for one third of the fleet as they begin making forays onto some of the islands in search of the reagents to produce the vaccine as well as rescue survivors. On one of those islands Sophia picks up a new crew member who's a little too competent in a fight and clearly lying about his past.

In one case they are rescuing the survivors of the television show Survivor that was being filmed on a small island. As always, Ringo shares the story of these Survivors in all its ridiculous pseudo-celebrity glory. That balances the more tragic description of the fall of Guantanamo Bay. The real adventure involves rescuing the space shuttle carrying the crew of the International Space Station the most important of which is an MD/PhD whose specialty is microbiology and well able to oversee production of a vaccine. That's assuming they don't crash, get eaten by zombies, catch the virus themselves, and she can be persuaded to work on a project that requires killing infected humans. 

This third book continues the mix of tragedy and humor I've come to expect from this series with a few new characters as well as a shift in the way our survivors are working. Instead of going boat to boat and saving who they can the fleet is taking on larger land based targets and training more people to help with the fight. What will they take on next?