It is 1884, and Molly and Cassandra Pepper, Emmett Lee, and Emmett’s long-lost father are sailing back to New York following their death-defying adventure in Antarctica. Having discovered a subterranean world at the South Pole while saving the world from certain doom once again, surely their accomplishments will finally earn them the recognition they deserve. But when their return to New York doesn’t go the way they’d planned, they decide that maybe it’s best to go into hiding. As the 1884 presidential election approaches, however, our heroes discover a plot against leading candidate Thomas Edison that only they can stop. It’ll be up to them to decide whether to come out of hiding, make the perilous journey to Washington, DC, and do the right thing one last time. Even if it means risking everything they have left.