Attentive young Sophie lives with her family at a lighthouse on the shore of Lake Superior. At this essential outpost, everyone has a job to do, whether baking bread, fishing for dinner, or caring for the light. And in this isolated place, in a time long before smartphones and Internet connections, news arrives only by ship, and information is sometimes gathered in unexpected places. Sophie is attuned to her natural surroundings, and she reads signs in a dandelion bloom, a spider's web, seagulls in flight, and even a squeaky door. All these clues lead her to one conclusion: a storm is brewing. Sophie scurries to spread the word--to family members tending the garden, hanging laundry, and picking blueberries. Most important, though: she needs to warn Papa of the impending change in the weather. As the lighthouse keeper, Papa maintains the foghorn, checks the light, and polishes its lens, his chores focused on keeping the signal working properly to warn ships away from treacherous rocks. Will Sophie reach Papa in time to alert him about the storm? And will the lighthouse be ready to guide nearby ships as the sky darkens and rain begins to fall?