The 69-year-old semi-retired private detective reluctantly takes the case of a Mrs. William B. Stone who seems to have lost track of her husband. Shanahan, who finds his once lonely life complicated by an attractive younger woman, nevertheless finds his client's husband almost immediately. But the job isn't over. The problem is the man is dead and buried in his own back yard. Who did it and why leads the detective to the city's meaner streets where the veil of secrecy is finally lifted.