When Lord Meriwell dies at his dining table, Nurse Veronica Haskell suspects foul play and notifies his lordship's doctor, eminent Harley Street specialist Dr. David Sanderson. In turn, compelled by a need to protect Veronica who is at Meriwell Hall as David's behest, David calls on his friends Barnaby and Penelope Adair for assistance. However, as the fateful dinner was the first of a house party being attended by the local MP and his family, the Metropolitan Police commissioners also consider the Adairs' presence desirable, and consequently, Barnaby and Penelope accompany Stokes to Meriwell Hall. There, they discover a gathering of the Meriwell family intended to impress the visiting Busseltons so that George Busselton, local MP, will agree to a marriage between his daughter and Lord Meriwell's eldest nephew, Stephen. But instead of any pleasant sojourn, the company find themselves confined to the hall and grounds while Stokes, Barnaby, and Penelope set about interviewing everyone and establishing facts, alibis, and the movements of those in the house. To our investigators' frustration, while determining the means proves straightforward, and opportunity reduces their suspect list, motive remains elusive, and their list of suspects stays stubbornly long. Then the killer strikes again, but even then, the investigators are left with the same suspects and too many potential reasons for the second death. What did the killer hope to gain? More importantly, will he kill again? At last, the investigators stumble on a promising clue, yet following it requires sending to London for information, and their frustration builds. As the clock ticks and they doggedly forge on, they uncover more and more facts, yet none allows them to identify which of their prime suspects is the murderer. Will they get the breakthrough they need, one sufficient to exonerate the innocent? When the answer arrives, they discover that the Meriwell family legacies are more far-reaching than anyone realized, and that the crimes involved and the motivation for the murders is far more heinous than anyone imagined.