The war between StarClan and the Place of No Stars could not have been won without the assistance of loners, many of which gave their lives in order to help save the Clans. The surviving loners took their rightful places as warriors in a Clan of their choosing, and they were accepted with honor, even the proud ShadowClan cats that call the pine forests their homes. Unbeknownst to the Clans, there was one loner who fought for their sake, who stayed in the shadows and never showed himself unless it was necessary.
Several loners had stories of him, this legendary hero they called the 'Clan of One.' He fought with the strength and speed of an entire Clan. No one ever managed to make out his fur color, or any markings he might have had. All they could tell their new Clans was that he had blue-green eyes that held the ferocity of a lion. Some loners even claimed he had fought in great battles all over, bringing victory to the side he had chosen to fight for.
Seasons have passed since the war. Four newleafs, to be more specific. Since then, the Clans have been at peace and growing in numbers. They have finally recovered to their former strength. But as always, they cannot live in peace for long. A new threat has appeared, a mysterious black cat claiming to be the Clan of One. He demanded hunting rights in all four territories in return for his assistance, and the Clans refused. Out of anger, this newcomer began to attack patrols and cats out hunting by themselves. Two ShadowClanners and a ThunderClan cat have already been killed. Several cats in all the Clans hang on the verge of death. Bramblestar of ThunderClan was the first cat to suggest they join forces once more to hunt down the Clan of One and chase him off, or even kill him if it comes to that. Border patrols now consist of at least five warriors, and the hunting patrols are now organized like Tribe hunts in the mountains; a few cats hunt while the rest act as guards.
United under this common threat, the four Clans haven't fought a single border skirmish in moons.