When Graystripe, deputy of ThunderClan, is captured by Twolegs and forced to be a housecat, he enlists the help of a feisty kittypet named Millie to find his way home.
Harboring growing suspicions about the trustworthiness of SkyClan newcomer Sol, a wary Leafstar is challenged to protect her clanmates when Sol's actions threaten everyone with disaster.