Subtraction — Sheila Deeth

Andrew Callaghan suspects his student Amy, who has gone missing, may have been murdered. With the help of Stella DeMaris, the school's new art instructor, he sets off on a road trip to find what happened to her. Tortured by memories of his own dead daughter, Andrew sees Amy's body in every passing shadow, while Stella, ever hopeful, sees cats. But where will the cats lead them, and will Amy be dead or alive at the end of the trail?