The world ends not with a bang, but with a downpour. Tornadoes spin through the heart of London, New York cooks in a heat wave that melts tarmac, and Russia freezes under an ever-thickening layer of permafrost. People rally at first—organizing aid drops and evacuating populations—but the weather is only getting worse. In Durham, mild-mannered academic Danny Fennick has battened down to sit out the storm. He grew up in the Scottish Highlands, so he’s seen harsh winters before. Besides, he has an advantage. He’s a werewolf. Or, to be precise, a weredog. Less impressive, but still useful. Except the other werewolves don’t believe this is any ordinary winter, and they’re coming down over the Wall to mark their new territory. Including Danny’s ex, Jack—the Crown Prince Pup of the Numitor’s pack—and the prince's brother, who wants to kill him. A wolf winter isn’t white. It’s red as blood.

When the Winter arrives, the Wolves will come down over the walls and eat little boys in their beds. Doctor Nicholas Blake might still be afraid of the dark, but the monsters his grandmother tormented him with as a child aren’t real. Or so he thought…until the sea freezes, the country grinds to a halt under the snow, and he finds a half-dead man bleeding out while a dead woman watches. Now his nightmares impinge on his waking life, and the only one who knows what’s going on is his unexpected patient. For Gregor it’s simple. The treacherous prophets mutilated him and stole his brother Jack, and he’s going to kill them for it. Without his wolf, it might be difficult, but he’ll be damned if anyone else gets to kill Jack—even if he has to enlist the help of his distractingly attractive, but very human, doctor. Except maybe the prophets want something worse than death, and maybe Nick is less human than Gregor believes. As the dead gather and the old stories come true, the two men will need each other if they’re going to rescue Jack and stop the prophets’ plan to loose something more terrible than the wolf winter.

Home. For Jack and Gregor, the exiled Wolf Princes of the Scottish pack, it’s someplace they never wanted to leave. For Danny, who fled as soon as he could, it’s someplace he never planned to return. As for Nick, pathologist and carrion bird, he has nowhere else to be. It offers only one thing—the Old Man’s help in putting down the bloody-handed treachery from the prophets who dogged them all the way from Durham. The twins’ father is many things, not all of them kind, but not even the prophets would cross him. But when they finally arrive home, they find the Old Man gone and the prophets’ puppet installed in his place. Outnumbered, bereaved, and haunted by old mistakes, the four of them must discover the prophet Rose’s plan before it’s too late. As the stakes rise and the cold settles into their bones, they find that the old fairy tales hide horrors under their pretty words. In the Highlands, Fenrir has stirred, and he’s hungry. The prophets have always said that a Wolf Winter is red as blood—but they never said whose.