Sam can't decide what he likes best about visiting Oak Island: adventures with his not-like-anyone-else grandfather, or dreaming about the pirate gold said to be buried at the Money Pit. But Sam and his sister, Beth, haven't been to Oak Island in almost three years - Grandpa and their mom had a terrible fight last time, and the two have stubbornly refused to speak to each other since. So Sam's a bit nervous as the ferry pulls into the harbour. And, just as he feared, everything is different. Grandpa's not waiting for them on the dock, and there are huge, frightening fences all around the Money Pit.

What starts to happen as soon as Sam sets foot on Oak Island is more exciting than he could have hoped for, more surprising even than the magic tricks he spends hours perfecting. As if dangerous run-ins with a monstrous digging machine and an explosive security guard, the discovery of a human skull and the lure of a real-life treasure hunt weren't enough to make this summer holiday memorable, Sam also discovers that, while Grandpa is losing his memory, he hasn't forgotten about what's important - like taking risks, bending the rules and refusing to let mysteries go unsolved.

His fingers gripping the edge of his seat, Rob decides the whole trip has been a really bad idea. The pilot of the tiny four-seater plane, looks crazy and his name is Crash. And while Rob and his twin, Mark, are en route to an island holiday, it's to King William Island in the middle of the Arctic Ocean - there'll be no surfing on this trip.

And then things turn bizarre. Rob and Mark are joining their scientist mother and her Institute's muskox-observing mission, but it turns out there aren't any muskox. No one can figure out why - except Mark and Rob. And where do they get their information? From an Arctic fox that leads them to discover a mysteriously etched human bone. And from an old Inuit man who appears out of nowhere to entrance them with eerie folk legends. When the twins find themselves suddenly speaking fluent Inuktitut and having nightmarish visions, Rob begins to long for the boring family vacation he thought this would be.