Cape Kidnappers, New Zealand: On a cliff overlooking the ocean and one of the largest gannet bird colonies in the world, American CEO Harlan Quinn has built his Plan B—a lavish estate, complete with an underground doomsday bunker. When the cleaning staff finds a body within, it appears the victim died of natural causes, but advanced facial decomposition leaves him unidentifiable. It can't be Quinn, according to his property manager/mistress and his wife back in the states, both of whom insist that the tech mogul is in Germany on business. But the uncooperative wife will not allow the police to search the main house for signs that the billionaire was on site, and so forensic odontologist Alexa Glock is called in to identify the body via dental records. Teeth never lie; the victim is indeed Harlan Quinn. All that's left is an autopsy to determine the cause of death.

But something odd in the deceased's mouth sets Alexa and the team on a new track—to find Quinn's murderer. As they work to narrow the suspect field, a second homicide—and a stolen cache of weapons from a locked room in the bunker—ramp up the investigation and the risk to Alexa's life. Will she be able to solve this particular riddle before she becomes victim #3?