Charlotte (Charley) Harris is a Pinkerton agent who goes undercover as a newspaper journalist to find a notorious train robber rumored to rob the inaugural trip of the Oversea Railroad to Key West. Allen Walker works security for Henry Flagler, the owner of the railroad, and takes on the persona of a photographer to ferret out any potential sabotage to the train’s success. What will happen when Charley and Allen suspect each other? Is the danger only to the train, or are their hearts in danger as well?