Lucifer is many things—more of a constellation than a single star, for all his ancient title. Sam, though, knows him better than most.

First comes rage.

Lucifer smiles when he's angry. He grins and snaps his fingers, making blood-and-bone confetti out of whoever has crossed him. He flexes the astral and atomic limits of his being, lets anger and exasperation, quick as a child's impatience and much, much deadlier, flicker along like embers.

When Lucifer is angry, he laughs.

Lucifer, angry, is the least of Sam's fears.

Next is vengeance. A shade different than wrath, and much, much darker. This is the betrayal of a son, and the betrayal of history. This is tears in the eyes of an angel, but when they fall the angel falls and Sam falls into the cage too, and Lucifer wants his brother to feel that pain, wants his father to feel that pain, and this all leads to Lucifer on the stage wearing the shell of a dried-up demigod. This is Lucifer, vengeful and freewheeling, spinning out of orbit, fatherless sun amid a range of pitiful planets.

And still, there is something that Sam fears more.

Sam fears Lucifer, content. Lucifer, knowing. Lucifer, victorious.

Sam held the doors tonight, and he freed the people, and he almost paid the price.

He only said Sam's name once. It curled through the air like a whiplash, casual and careless. Lucifer, still vengeful and desperate, has not yet won.

He only wins with Sam.

That was Detroit.

That was faces in a mirror, broken glass inside his head.

Lucifer, when he rises above his most strangely human tendencies—anger, despair, bitterness—is more like the gods the ancient peoples feared than any carven idol could ever be.

Sam in the cage, Sam out of the cage. Sam always has something Lucifer wants.

When Lucifer gets it, that's when Sam will be afraid.