DEAD MEAT by Patrick Williams and Chris Williams is not about friendship or working together, but instead focuses on the combination of hate & fear that arises when random strangers form a loose-knit group, and they are unable to agree on much of anything. Conflict dominates their decision-making, rather than the motivation to live. They way they see it, they're all going to die, but it's a battle to see who dies last. Not only does it explore the various shades of gray when it comes to the kill or be killed theme, but it's a gripping account of endurance with incredibly raw characters.
I like the way various groups are labeled; the zombies are called "bees" because of the way they swarm around the survivors. The soldiers are called the "Exterminators" as they quickly become more of a threat than the undead, using live bait to draw in the bees. These labels used by the characters create the illusion of compassion among the group, when in reality, the survivors often give in to their own savage impulses, striking out at their traveling companions at the worst of times, leaving readers to wonder which group is doing the most damage.
This novel is a visceral account of a hopeless attempt to reclaim something worth living for, with the narrator coming to a brutal realization about his first impressions. The ending will gnaw at your insides long after you finish the story.