Unfamiliar with the ways of Twolegplace, and his memories of wild life fast fading, Graystripe almost sinks into despair, but Millie helps him, and he trains her as a warrior, recalling his own love of the wild. During the events of Dawn, he was captured by Twolegs, and adopted by a loving family. Graystripe – the main character, a kidnapped warrior of ThunderClan.What they don't realize is that ThunderClan, along with the rest of the Clans, no longer resides in the forest. Then the two set off to try to find ThunderClan. Millie nurses him back to health and asks him about Silverstream. Upon meeting him, she discovers him feverish and weak he even calls her by Silverstream's name. Millie changes her mind and goes out to catch up to Graystripe.

Graystripe ends up getting lost in Twolegplace for days before collapsing from exhaustion. Later, Graystripe asks Millie to come with him to ThunderClan, and is taken aback at her refusal. She also tells him that he already has a traveling companion. In another dream about Silverstream, after Graystripe tells Silverstream that he wishes he could be with her, Silverstream reminds him that his place is with ThunderClan. After a dream in which he is visited by his deceased mate, Silverstream, and his daughter Feathertail, and another fight with Duke and his allies, Graystripe finally makes the decision to try to return to ThunderClan. She then shows it to Graystripe and asks him to teach her how to hunt and fight after learning of his previous life. The two cats get to know each other better and Millie finds a small forest in the middle of the Twolegplace. After being forced to flee the fight, Graystripe is led back to the nest he has been staying in by a female kittypet named Millie he meets, who assures him that losing to Duke is nothing to be ashamed of. He makes an attempt to flee but gets lost in Twolegplace and battles with a kittypet named Duke. He somewhat likes the Twolegs and their kits but he cannot stand to be away from his Clan and his fellow warriors. He is then taken in as a house cat by a Twoleg (human) family. The Lost Warrior opens with narration from Graystripe, a warrior who was separated from his Clan, ThunderClan, after being kidnapped by humans while trying to deforest his home. It follows Graystripe's adventures trying to escape from the Twolegs, who have taken him in as their kittypet.

The manga was published by the distributor Tokyopop, and was released on 24 April 2007. The Lost Warrior is the first in an original English-language manga trilogy based on the best-selling book series Warriors by Erin Hunter.

Warriors the lost warrior