Erin Hunter 
Survivors #3: Darkness Falls 

From Erin Hunter, #1 nationally bestselling author of Warriors, comes the third book in the action-packed Survivors animal fantasy series. Full of wild and wonderful adventure (Kirkus Reviews, starred review), Survivors will thrill fans of Spirit Animals and Wings of Fire.The Wild Packs ruthless Alpha has reluctantly agreed to allow the Leashed Dogs to join his Packbut not before learning of Luckys role as a spy, and casting him out of the Pack forever. Lucky tries to be happy to have his freedom again, but this new world is treacherous for a Lone Dog. For the first time since the Big Growl, Lucky is desperate to have other dogs by his side . . . but it might be too late.