American detective Dan Elliot and his wife, Caroline, have traveled to Nice, France, to witness the wedding of their special friend, Kate Kennelly, and the wealthy Jack Boulanger. Caroline's daughter, Ruth Mannering, is serving as the maid of honor for this elegant wedding. But when Ruth and Kate don't arrive at the church for the start of the service, concern sets in.
Hours later, Ruth regains consciousness on a seedy side street in Nice, and she's able to alert her parents that Kate has been kidnapped. From the moment the two women disappear, someone taunts and terrorizes the groom and his family. The culprit is called the "hyene" because of the childish song and nursery rhyme parodies that have been sent to Jack. Dan and Caroline share their unique crime-solving expertise with France's premier detective, Emile LaGrange. When kidnapping escalates to murder, Caroline does not let her disability hold her back as she, Dan, and LaGrange seek to reveal the identity of the kidnapper and murderer. Tension escalates as other deadly incidents unfold, and the detective trio must determine if this case revolves around ransom, jealousy, or revenge.