John Peters is an archaeologist who left his Ivy League university after an unfounded accusation of plagiarism in his dissertation. He reaches out to his old tutor at Oxford and is soon enlisted in an archaeological expedition to find the long lost tomb of Alexander the Great. But the expedition turns out to be a cover for a CIA and MI6 operation that puts Peters and his new girl friend and colleague Lady Liz Armstrong in harm's way. Searching for Alexander's tomb turns out to be the last thing that Peters and Armstrong need to worry about.

Just back from their worldwide tour exhibiting the treasure they had found after locating the long lost tomb of Alexander the Great, John Peters and his wife Liz along with their friends Harry Roberts and Meg are entangled in another archaeological mystery, this time in the Mayan area of Mexico. Once more they become entangled with eco terrorists while untangling the mystery of the missing Devil's Dagger, a Mayan treasure stolen from the National Museum in Mexico City and which is the key to finding a lost underwater city.