The City Spies are ready to start fresh with a new home, new schools, and a new directive now that Clementine has come in from the cold and Le Fantôme has been put behind bars. But their plans are put into jeopardy when Umbra threatens to attack multiple high-level targets across Europe unless he is released from prison. With intel leading them to Rome, Paris, London, and Amsterdam, the City Spies split up and race across the continent solving codes and chasing clues in an effort to thwart the attacks. With so many moving parts, the City Spies are going to have pull out all the stops if they have any chance to succeed at this latest mission.