Celestial Mechanics: a tale for a mid-winter night

"In this novel of haunted love, Silas Fortunato, an amateur astronomer, finds his marriage descending toward darkness until the arrival of his sister-in-law and soon thereafter the appearance of a witching neighbor who may or may not exist. Enigmatic, ghostly, and funny, the three women draw him into the equivocal nature of reality and dreams, and lead him on a journey toward something vastly beyond himself."--Jacket flap.