For moons so many that no creature can count them, the four Clans of creatures: SeaClan of the ocean, StoneClan of the mountains, StormClan of the moorlands and SecretClan of the valleys and marshes - lived together in (mostly) peace. Except for the occasional squabbles over prey and territory, they prospered and grew in happiness and contentment.
But all that ended when the Nightprowlers came.
The Nightprowlers! Ruthless, cold-blooded murderers, hungry for territory and the spilt blood of the Clans. Those slinking shadows that haunt every Clan-creature's nightmares. They steal prey, kill creatures. Since they came, no Clan-creature can go out alone without looking constantly over his or her shoulder. Too many have died. Nowhere is there safety.
And at last, the storms of battle are sweeping over the lands.