"Warriors: Into the Wild" is the first book in the Warriors series by Erin Hunter. It follows the journey of a domestic cat named Rusty who dreams of adventure beyond his home. He joins a group of wild cats known as ThunderClan, where he learns about their ways and the challenges they face in the forest. As Rusty adapts to his new life, he takes on the name Firepaw and becomes a warrior apprentice. The story explores themes of friendship, loyalty, and the struggle for survival in a world filled with rival clans and dangers from both nature and other cats.