Shadows on the Rock tells the story of a father and his young daughter during the long months between October, when the first ship for France passes out of sight down the St. Lawrence, and the following July when the Colony's isolation is ended by the ships' return. Count Frontenac, the Governor of New France, impatiently awaits his recall from Canada by Louis XIV.

Auclair and Cecile live in the street that connects the Upper Town on the cliff with the Lower Town beside the river at the foot of the mountain. Every phase of the seasons, from the heavy snowfalls in December to the spring downpours and the ice in the river breaking up and floating down stream in huge great blocks is extraordinarily vividly described. At the end, Frontenac dies, and with him all hope of the Auclairs being able to return to France. Their mood however is far from being one of despair. Pierre Charron, a hunter who has travelled as far as Lake Superior in his search for furs returns from the wilderness to marry Cecile and his knowledge of the woods and the people of Canada is security enough to guarantee their future.