Danger Boy and his time-traveling companions are in for some shocking surprises when they meet up with an earlier expedition — the historical journey of Lewis and Clark.

Fresh from a dangerous time-traveling mission, Eli Sands and his friends Clyne, the evolved dinosaur, and Thea, the scholar from Alexandria, are thrown into nineteenth-century America after an accident with their time-travel vessel. Unfortunately, Clyne is stranded alone in potentially hostile territory, while Thea and Eli pop up at the beginning of the famed Lewis and Clark expedition. After Thea is mistaken for an escaped slave and taken into custody, Eli joins Lewis and Clark's Corps of Discovery in hopes of finding Clyne, a means to rescue Thea, and transportation home. While trying to escape and regroup, Eli and his friends make important discoveries about their "accidental" stumble into 1804. It looks like they were lured by a Prime Nexus, which they may have caused, and which will surely change all of history to come.