A romance develops as a detective partners with a lonely-hearts columnist to solve a murder mystery.

London, 1885. Amelie Hampton is a hopeless romantic, which makes her the perfect columnist to answer lonely heart letters in the Marriage Gazette. When Amelie plays matchmaker with two anonymous lonely hearts, she also decides to secretly observe the couple's blind date. To her surprise, the man who appears for the rendezvous is Harold Radcliffe—a grieving widower and a member of Amelie's book club.

Police detective Michael Baker has been struggling ever since his best friend and brother-in-law died in the line of fire. Because he knows the dangers of his job, he has vowed never to marry and subject a wife and family to the uncertainty of his profession. But when he meets Miss Hampton, he is captured by her innocence, beauty, and quick mind.

When a woman's body is pulled from the river, Michael suspects the woman's husband—Harold Radcliffe—of foul play. Amelie refuses to believe that Harold is capable of such violence but agrees to help, imagining it will be like one of her favorite mystery novels. Her social connections and clever observations prove an asset to the case, and Amelie is determined to prove Mr. Radcliffe's innocence. But the more time Amelie and Michael spend together, the more they trust each other and the more they realize they are a good team—maybe the perfect match.

They also realize that Mr. Radcliffe is hiding more than one secret, and when his attention turns toward Amelie, Michael knows he must put an end to this case before the woman he loves comes to harm.