A complex tale of mistaken identities involving duplicates, triplicates, and more. Tricia begins to meet herself everywhere she goes. The woman who looks like her appears to be trying to take over her life, her house, her husband. Is the woman real, or is this an elaborate ruse to cause her to doubt her own sanity? If it is, who would be able to pull off such a ruse except the one person who knows her best? As duplicates pile up, and eventually an imaginary "friend" comes to life and begins to add to the torment, Tricia realizes she must figure out what is happening unless she wants to lose her mind. As a scientist, she is unable to accept many of the wilder explanations offered when people appear and disappear, seemingly out of nowhere, but she can find no logical explanation for the strange phenomena.

In which a college teacher is at first startled and then bedeviled by an alter ego who keeps bumping into her quotidian affairs, before long accompanied by a duplicate of her husband and various other people in her life, replicas who are often rather threatening. The professor soon begins to doubt her own sanity and the integrity of her husband. The imposters continually berate her for intruding on their world, and the web is cast wider still when her psychologist begins encountering an ill-tempered version of her imaginary friend. This is a fascinating premise wrought by a talented author who has sweat the details to make the reader able to untangle this knot, so that doubt is put into the reader's mind when a character appears, but when clarity is required, that is offered as well.