They saved a town with the help of the creatures that command the geysers. They saved a city from volcanic eruption. Surely they've earned a break? Tell that to the Titanosaur. Now the faultline network is active, threatening all of central New Zealand with aftershocks that might be bigger than the initial event. Amateur geologist Anira Fraser is in Picton, facing her final high school athletics competition. Along with her friend Tiger McRae, she realises their presence is disturbing the area's guardian spirits. Soon other Earthcore members arrive in town and discover an old enemy stirring up fresh trouble, while the locals hint at the legend of a mysterious taniwha war that could worsen the series of quakes. It's up to Anira and the Earthcore team to find the cause of the war and end it—otherwise they themselves could be responsible for a cataclysmic natural disaster.