The Grinning Tun is a sea shell, plucked from the sands of a faraway tropical shore. But this is a sea shell with a difference. It will not stay put. Shove it in the warming oven and, next morning, it sits on top of the stove. Bury it in the ground and it is found in the root cellar. And it grins. It thinks of the possibilities.In the 1990s, Kaye Eliot comes to Acadia Creek to spend a quiet summer with her two children. But instead of passing stress-free days of swimming and hiking, she finds herself embedded in mystery after mystery. A missing vagrant and a gang of thieves have the community worried. Neighbours seem determined to occupy all of Kaye's time and energy in restoration of an old flower garden. To add to the mayhem, Kaye and her kids have stumbled on a century-old legend of a treasure buried on the property, a packet of forgotten letters from a woman named Maria and an old map of the garden. And they dig up a sinister sea shell. A sea shell who looks like a grinning skull and will not stay where he is put. Can Kaye recover her calm or will she be the victim of neighbors, vagrants, thieves and a shell called the Grinning Tun? Restoring Maria's garden seems a great idea, until Kaye discovers how Maria's garden grew.