In Acapulco, Hercule Poirot attends a dinner party in which one of the guests clutches his throat and suddenly dies. The causes seem to be natural until another party with most of the same guests produces another corpse.

After the disappearance of a young scientist on a business trip, his son and wife struggle to cope, only to make a bizarre discovery years later - one that may bring him home.

Sherlock Holmes is drawn into the case of Jack the Ripper who is killing prostitutes in London's East End. Assisted by Dr. Watson, and using information provided by a renowned psychic, Robert Lees, Holmes finds that the murders may have its roots in a Royal indiscretion and that a cover-up is being managed by politicians at the highest level, all of whom happen to be Masons.