A newcomer to Mayfair charms the socks off of Susanna Mayfair, the sheltered niece of the town's elderly matriarch. In a panic, the aunt turns to service dog trainer Marcia Banks to dig into the man's past.

What Marcia finds, with her detective husband Will's help, is disturbing—a trail of broken hearts and outstanding warrants. But when the older gentleman is arrested, he claims it's a case of mistaken identity.

While Will attempts to untangle the truth and Susanna struggles with her feelings, Marcia is worried about her friend's mental health, unaware that Susanna may be in physical danger as well. Can Marcia figure it out in time to protect Susanna...and herself?