Of course it is. All that blood spilled on the fabric. The stains left over from when it was carried to hell, and heaven, and purgatory by a divine being. The lake water and tears and stardust soaked up into the seams.
It was held together and repaired by the will of its host. And now it’s a nexus of stalled energies and broken breath. It’s a graveyard.
Castiel the angel never noticed the whispers. But Cas the human hears them all the time.
He wears the coat anyway. Because it’s a part of him. And he comes to understand a lot about futility and desperation.
He won’t take it hunting, it’s too much of a distraction. But everywhere else he goes, the coat goes with him. He starts taking long walks just to listen. Wearing it even on hot summer days. He carries around his weight in specters; restless spirits curled up in the pockets. They are the people he killed, the demons he slew, and the people he couldn’t save.
And one ghost who can’t remember its name. Who sleeps in the breast pocket, close to the thumping of Cas’ heart.
The other ghosts want to talk about grief and revenge. They go on and on and on about pain and darkness, or how much they miss the sensation of dreaming.
The breast pocket ghost only wants to talk about astronomy. “The north star isn’t the brightest star in the sky, you know,” he says. “Sirius is.”
"I didn’t know that," Cas replies softly. Sadly. Dry dirt road crunches under his feet.
"It’s in the constellation Canis Major," says the ghost. Then there is almost quiet for a while, as Cas walks and the breast pocket ghost hums. This is the only time the other spirits stop their clammer. They won’t speak over this ghost. Cas can’t tell if it’s out of respect, or just because they fear him. “Have I ever told you what comets are like?" the ghost asks after a minute.
"Yes," answers Cas. His voice breaks only a little. “But please tell me again."