Firestar was a kittypet who lived with his housefolk in Twoleg place in the old forest. Most of the first series focuses on his rise to power. Rusty (Firestar's kittypet name) had prophetic dreams about the vigorous hunting in the forest, and wanted to try it out for himself. One night, after waking up from a mouse-hunting dream, Rusty ventured into the forest and accidentally strayed into ThunderClan territory. He was invited to join the Clan (but mainly because of the prophecy Bluestar had recieved) and he accepted. He was eventually renamed Firepaw, and is the beloved Clan leader Firestar that we know today.