Book 23 in the highly successful Imagination Station series finds cousins Beth and Patrick nearing Washington, D.C., on the train with Abraham Lincoln, heading to his first inauguration. But a band of assassins plan to meet Lincoln in Baltimore and end his presidency before it starts. Can the cousins help get him through the city safely and on to his big history-making day?

While each Imagination Station book stands on its own, books 22-24 form a three-part story arc covering the Civil War.