While attending an exhibition at the Crystal Palace, young cook Kat Holloway is approached by a woman in distress. Lady Covington is a wealthy widow convinced that her entire family is trying to kill her. Kat feels compelled to help, so she escorts the lady home to discover whether she is delusional or in true danger. When it quickly becomes apparent that the threat is all too real, Kat promises aid. Her charming confidant Daniel McAdam is busy infiltrating a plot against the Crown, and she worries he will not have time to lend his sleuthing expertise. This might be for the best, as Kat fears her growing emotional entanglement with Daniel can only lead to disaster. But soon, Kat faces a more serious threat when her involvement in both investigations plunges her into peril.