The construction of a massive bridge across the Straits of Mackinac in 1957 threatens to end a family's livelihood and alter a young boy's world. Mark, thirteen, and his younger brother Luke are initially thrilled by the prospect of the five-mile bridge, a marvel of modern engineering that promises to connect Michigan's peninsulas. However, their excitement is tempered by the reality that their father's ferry boat business will soon become obsolete. As the bridge's construction progresses, Mark must grapple with the changing economic landscape and his own evolving understanding of progress and tradition.

The premise sets up a compelling narrative exploring the personal impact of historical infrastructure development. The focus on a young protagonist suggests a coming-of-age story intertwined with broader societal shifts. The historical setting of the Mackinac Bridge construction provides a rich context for themes of change and adaptation. The story likely examines the emotional and economic consequences of progress on a family and their community.