Task Force is a book based in the future. It is about, what a surprise, a task force, whose mission is to cripple an alien invasion before it even begins. The task force is compromised of teenagers, who are altered and trained to look, talk, and think like the alien invaders. Their part of the mission is to clear a path for a preemptive force from the humans by taking out electricity in the Alien's city that they set up on earth, and guiding the large human force into the alien's city.
In this story, there is a tribe, divided into three groups, which needs to unite and declare war on their common enemy. They get a new leader who unites them and pushes the enemy out. There are a lot of battle scenes, and a lot of different characters come into play. The author's purpose seems to be to entertain the reader about an ancient tribal war. There are a lot of displays of leadership and bravery. I would say this book would fit into the action genre.