After marrying, amateur detective Lord Peter Wimsey (Robert Montgomery) and mystery novelist Harriet Vane (Constance Cummings) agree to retire from their sleuthing interests. Along with their devoted butler, Bunter (Seymour Hicks), the couple sets off on a honeymoon to Harriet’s old family cottage in Devon, which Peter has purchased for Harriet. The day after their arrival, a dead body is found at the cottage and, despite their best efforts, Peter and Harriet are drawn into the investigation.