Diana Egremont is seeing things--specifically, the ghost of a nonexistent twin sister--so she convinces old acquaintance Candida Brown to stay with her in Tower Abbey, Westchester Co. Candida, an animal lover and rationalist, brings eight pets, doesn't believe in ghosts, and assumes that Diana's flakiness comes from her drinking problem--until she too feels the uncanny.chill in a certain bedroom, is pushed down a disused staircase by unseen hands, and is almost done to death twice by hallucination. When Diana's young son James pops up--complete with black cat Hannibal and an imaginary secret kingdom--Candida is worried, since the house has a history of child victims (two eight-year-olds down a well for starters). And Candida's childhood crush Simon, now an Episcopal priest, shows up too, as well as old friend Eric (who keeps warning her against Simon). With buried treasure and unearthed murders and a spiffy exorcism and all those pets, there's lots of extra yardage here--along with a few too many furbelows (does poor Candida have to have a sex problem on top of everything else?). But the fabrication and stitching are first class.