When Lupin looks up from his book again, Snape is still there.
His eyes look wet and decomposed, and his hair is something the colour of dried blood. Blood also covers his white-veined hands as he holds them out to Lupin accusingly.
"Perfectly ridiculous," Lupin mutters, shaking his head and going back to his reading. The librarian looks at him askance as she wheels her creaky cart right through the empty space where Snape stands. The pages of the book are dry under Lupin's fingertips, and make a harsh, old sound rubbing together.
On the train, commuters move through Snape without a shudder. The cold belongs to Lupin alone. Lupin closes his eyes and tries to feel only the rocking of the subway car, brows knit. He can still see the pale skin on Snape's bloody arm where the Dark Mark should be.
In the nighttime, something scratches lightly and repetitively at Lupin's front door, like a cat wanting in. For nearly a month, Lupin ignores it, reading or listening to the radio. No one is there to be impressed by his mask of disinterested calm.
On the night of the new moon, Lupin throws his book through the window. When the shattered glass goes quiet, the scratching hasn't stopped.
Lupin opens the door. Snape stands on the threshold, dead-eyed.
"Why do you keep following me?" Lupin says. "Why don't you go where you belong?" (There's no doubt where Lupin means.)
Snape opens his grey mouth and draws in a dry, cold breath — Dementorlike. His voice is slow, and crackles like leaves.
"Because Black is there, too."
Lupin slams the door violently shut and turns, walks quickly toward his bedroom, the bottoms of his feet tingling like vertigo.
In the pressure at the back of his neck, he can feel Snape following close behind.