Derek likes fur to skin contact, so he just lets out a content rumble as Dean pets him. He knows that Dean is hurt, and needs to be kept safe and warm. Derek burrows closer, and his ears perk up when Castiel is suddenly outside. He smells angry and he's loud, so Derek leans down and shoves his muzzle up under Dean's shirt, wriggling underneath it until his whole head is under the fabric and they're pressed together.

Something smells like apples and cinnamon, though, and Derek's wet nose pokes out through the neck of Dean's shirt, pressing up under his chin as he sniffs curiously.