Thunder the dog likes to take naps by the sunny window, sniff around for hidden treats, play fetch, and get cuddles from her favorite human, Sage. Though Thunder wants to be good for Sage, she's having a ruff time stopping herself from doing things she knows are wrong-like barking, digging, and chasing suspicious furballs around the yard. She's shocked when her inner Wolf appears one day and reveals the truth behind these irresistible impulses. It's all because dogs are really wolves! (That is, they're descended from them.) The big question is: Will Thunder choose to be a loyal pet to Sage, or embrace the wild animal within?