Music professor Gus LeGarde is about to embark on a European honeymoon with his new wife, Camille, when his socially challenged brother-in-law receives a mysterious invitation to visit an ailing relative in Germany. Siegfried can't travel alone, but the newlyweds have no qualms over bringing him along.Unfortunately, their idyllic vacation takes a dark turn at the first stop in Paris, when Gus and Siegfried are caught in a bloody street brawl with a group of neo-Nazis -- and a flawed news report frames Siegfried for the murder of one of their leaders, thrusting him into the deadly group's crosshairs.After a narrow escape, Gus manages to bring his brother-in-law safely to Germany, where he hopes to both salvage the rest of the honeymoon and explore the shocking family secret that awaits there. But the events they've set in motion have far-reaching consequences, and the ruthless leader of the terrorist faction has lethal plans in store for Gus, Camille, and Siegfried -- and ultimately, the world.