The Earth is destroyed, everyone indoors is dead. Carl and his cat, Princess Donut, have survived through sheer luck. The Borant Corporation forces the survivors into The World Dungeon, a reality program they are running.
In a dungeon full of monsters, NPC and other crawlers, their goal is to survive. They are assigned a mentor, Mordecai, who will help them through the ordeal.
Fighting monsters, including dungeon bosses, and occasionally other crawlers, they gain fame, fortune and viewers, and ultimately a PR agent, Zev. Occasionally they receive a reward box containing magic items that (should) help them in their quest.
The book is very funny in its ridiculous situations and unexpected events. It feels very much like the 70s-style of dungeon crawls.