After failure after failure, the Hardy Boys go to a strange drilling site and find the Infinity clue there too. While staying at camp, they witness a boat disguised as carrying oysters passing by. The Hardy Boys witness strange flashes and go to the source to investigate.
After they arrive in Washington, DC, they are threatened by a ruthless terrorist who seems to have a hobby with explosives. The Infinity clue seems to turn up everywhere and a supposedly cursed diamond is stolen. The Hardy Boys are suspect of stealing the diamond and take on this new case to try to clear their name.