Warriors manga (Erin Hunter). Original series

When the Twolegs destroy the warrior Clans' forest home, Graystripe who is second in command of ThunderClan is captured trying to help his comrades escape! Trapped in the pampered life of a kittypet, Graystripe has all the food and shelter he needs from his affectionate Twoleg family, but this is not the way he wants to live. The forest is calling him, and he never stops longing to go home. When he makes friends with a feisty kittypet named Millie,...

Describes the adventures of Graystripe, a former leader of ThunderClan, as he struggles between staying with his adopted Twoleg family and embarking on a quest to find his lost feline companions.