Tigerclaw took firepaw on his first apprentice training session. It is a part of the Warrior series. Warriors is a series of novels that are published by Harper Collins; it's written by authors Kate Cary, Cherith Baldry, Tui Sutherland, with the plot developed by editor Victoria Holmes, who together use the name Erin Hunter. The series follows the adventures of 4 Clans intelligent cats—ThunderClan, ShadowClan, WindClan, and RiverClan —in their forest and lake homes, that watch out to StarClan, their warriors ancestors, and spirits within the stars, who guide the four clans.
SkyClan, the long-forgotten fifth kin group of the forest, is later introduced within the complete novel Firestar's Quest. It receives further focus within the novel SkyClan's Destiny, the manga trio SkyClan and also the stranger, and the 2013 novel Cloudstar's Journey.