Alvin, the twenty-one year old director of the British Museum is worried as the security of the Royal Incan Diamond is at stake after the recent robbery attempt at the museum. The museum was built by his ancestor over two hundred years ago and after his father's death, he inherited the Incan Diamond.
The plot begins with Alvin's uncle trying to protect the Diamond from the thieves. He hides the Diamond at a safe spot and sends a conundrum to Alvin, decoding which would unveil the Diamond's place. He gets killed soon after. The rest of the book is about Alvin's thrilling experiences while solving his uncle's puzzle during which he also discovers important ancestral secrets connected with the Diamond.
