Unlike other books in the series, this one does not take the adventuring duo into exotic places faraway from the United States. It is the only time when the events take place wholly in their home city of New York. This is also the only instance when the day of the action can be dated - on Saint Patrick's Day, March 17. Richard received an urgent plea from an old acquaintance for a meeting at the Central Park Zoo on Saint Patrick's Day. The acquaintance was introduced only by his first name, Ralph, was a gentlemancon of the old school who was described as having a rich imagination and leave his victims "still feeling good" because of the fortune they almost made. Stephen had gone along with Richard to the zoo, but his presence distressed Ralph who was alarmed at the thought of a kid getting involved as the matter was very serious. Before Ralph could reveal more, he was shot and was incapacitated, and his assaillant disappeared among the crowd. The only clue was a business card where Ralph listed himself as President of a company named Secucomp, Inc.. Ralph carried a lot of business cards listing his first name with different last names, with impressive designations for a variety of companies. But Secucomp stood out because it had a real corporate address. As it was set in their home city, this book had Stephen's mother and father playing greater roles in the story, including aiding them in their investigation. Along the way, they discovered their nemesis was only other possessor of the Kronom K-D2 watch in the world. Known as the Mole, or as the Money Master when he made threat in the New York Stock Exchange, he hacked into the Stock Exchange's computer systems and demanded submission from all world banks around the world. Too late, Richard realised that he is up against the only person in the world who knows how to use the Kronom better than himself, perhaps even better Karl Wolfmann, the Kronom's inventor. The Mole had been Wolfmann's assistant, but his active participation in the final refinements of the Kronom gave him an intimate knowledge of its capabilities and a definite edge over other users of the Kronom.
Non-recurring Characters
Ralph, last name not revealed. Ralph is from Brooklyn, but in playing his role as a confidence man, he dressed and spoke like an old school British gentleman. He knew Richard Duffy well enough from the past to turn to the latter for help when he found himself in a scam that was beyond his depth.
Janice Bruce. A computer science graduate who grew up in Silicon Valley. She was employed in Secucomp to as an IT security expert.
Mr. Hackermeyer. An ill-dressed nondescript appearing accountant employed by Secucomp.
Donovan. A New York police who knows Richard from the past.
The Mole. Richard's ultimate adversary who helped designed the Kronom K-D2. In chapter eleven, he revealed that he chose St. Patrick's Day, which was also his 44th birthday, to launch his biggest caper.