Demon's Door — Graham Masterton

Remedial English teacher and psychic Jim Rook has been feeling out of sorts all summer, and on the first day of the Fall semester he runs over and kills his pet cat, Tiddles. But halfway through his first class, enigmatic new Korean student Kim Dong Wook arrives . . . with a gift: a basket containing Tiddles, alive once more. The Korean spirit Kwisin, Jim is told, is saying "thank you" in advance. But what for? Jim can't help but feel deeply uneasy . . .