Tory Brennan - great niece of Dr Temperance Brennan - and the Virals return for their most terrifying adventure yet. Life appears peaceful on Loggerhead Island - rescued from financial disaster, the research institute is flourishing once more. But the tranquility is quickly shattered when Tory Brennan and her technophile gang discover a mysterious box buried in the ground.

A seemingly innocent treasure hunt soon turns into a nightmarish game of puzzles, as it becomes clear that one false move will lead to terrible, explosive consequences. The clock is ticking. Can Tory and the Virals crack the code in time to save the city - and their own lives?