The human race destroyed itself with nuclear weapons. Mice and rats have become the dominant life forms and are now at war. The mice have formed a military force which they name, appropriately, the Mouse Marines. This series tells the story of one group of these marines, led by a mouse called Tiny. Tiny fears that there may be dissension in the ranks because he wants to pursue an investigation into the suspicious death of his friend Jerry. To stop him from investigating, Tiny feels that he has been sent on a suicide mission. The series chronicles the adventures of Tiny and his crew as they fight both the rats, and their own population.This one-shot concludes the Mighty Tiny Mouse Marines storyline that ran as a backup story in Mighty Tiny #1–4.