From Erin Hunter, #1 nationally bestselling author of Warriors, comes the New York Times bestselling second book in the Survivors series. Praised by Kirkus Reviews as "perfectly crafted" in a starred review, A Hidden Enemy is an action-packed adventure that will thrill fans of Spirit Animals and Wings of Fire. After discovering a forest filled with prey and fresh water, Lucky and the Leashed Dogs are sure that they have found their new home. But a fierce pack of Wild Dogs has laid claim to the land and their menacing Alpha won't allow other dogs to settle there. Now Lucky finds himself forced to go behind enemy lines—and to decide which dogs will ultimately be his true allies.