The 'Dirty Dozen' based on a true story is probably centered around a group of twelve people. These people are likely to be from a rough background, perhaps having committed crimes or being outcasts in some way. In the story, they are recruited for a specific task. This task is likely to be extremely challenging and dangerous, such as a military operation behind enemy lines. The story may explore how they overcome their differences and personal issues to achieve success in this mission. It could also show the moral and ethical dilemmas they face during the process.