When private detective Lucy Trimble is retained by Greta Golden to find the identity of the ominous lurking stranger who Greta is certain is following her, it doesn't appear to be too challenging a mystery. Lucy has no trouble learning who her client's pursuer is: a British investigator has been engaged to probe into Greta's life. But the question of what he is trying to discover about Greta, and why, begins to truly complicate the case.

This revelation soon opens up further questions about Greta's own identity and, more specifically, the identities of her mother and father. Lucy's investigation leads her to Cornwall, England, where there still live witnesses to Greta's birth and her father's death. Lucy slowly begins to put the fragments of the puzzle together, but it is only when Greta joins Lucy in England that she is able to find the missing piece, and begins to confront her own rapidly evolving and more complicated personal life.