The Cipher - Kathe Koja

Nicholas is a would-be poet and video-store clerk with a weeping hole in his hand - weeping not blood, but a plasma of tears... It began with Nakota and her crooked grin. She had to see the dark hole in the storage room down the hall. She had to make love to Nicholas beside it, and stare into its secretive, promising depths. Then Nakota began her experiments: First, she put an insect into the hole. Then a mouse... Now from down the hall, the black hole calls out to Nicholas every day and every night. And he will go to it. Because it has already seared his flesh, infected his soul, and started him on a journey of obsession - through its soothing, blank darkness into the blinding core of terror...