Reeling from the loss of her parents, Lucy Clairmont discovers an artifact under the floorboards of their London flat, leading her to an old seaside estate. Aided by her childhood friend Dashel, a renowned forensic astronomer, they start to unravel a history of heartbreak, sacrifice and love begun 200 years prior --- one that may offer the healing each seeks.

In the wake of WWII, a grieving fisherman submits a poem to a local newspaper asking readers to send rocks in honor of loved ones to create something life-giving --- but the building halts when tragedy strikes. Decades later, Annie returns to the coastal Maine town where stone ruins spark her curiosity and her search for answers faces a battle against time.