Nat Sheppard’s world is turned upside down on the first day of the school holidays by the discovery of a secret room containing cave maps with clues to an ancient treasure. But Nat and her friends soon discover they’re not the only ones chasing the jewels. Professional treasure hunters are on the trail – and they’re prepared to eliminate anyone in their way.Nat Sheppard is devastated when her father announces on the first day of the school holidays that the family farm is going on the market. But then her world is turned upside down by the discovery of a secret room in their attic. Inside is an unopened letter addressed to Nat’s great, great grandmother, a copy of Sinbad the Sailor, and two cave maps with clues to an ancient treasure. In their quest to find the treasure and save the farm, Nat, her brother Jack and their friends realise that they're not the only ones chasing the jewels - professional treasure hunters are also on the trail.The children have to stay one step ahead of the treasure hunters, but even with the help of Abraham Te Kaitiaki, a local elder, their escapades don't always go to plan. Nat gets knocked out, her sister goes missing, and as a huge storm settles in, everyone is grounded. The children sneak out and swim into the cave just as the treasure hunters are drilling through from the other side, but Jack gets caught in a rock fall. Nat has to save her brother, outwit the bad guys and get the treasure - and the water is rising. The Secret of Sinbad’s Cave takes the myths and mysteries of Aotearoa and weaves them together into a page turning adventure, while offering a compelling alternative history of New Zealand.