As the true identities of the CP9 assassins are revealed, so is their real motive--to get their hands on the blueprints for the Pluton, the most destructive weapon of the ancient world! With Robin leaving the crew of her own free will, the CP9 won't let anything stand in the way of their mission... least of all the Straw Hats!
After leaving the Straw Hat Pirates, Robin is heading to the naval base, Enies Lobby, with CP9. Her tragic fate is to be executed. Luffy and the crew, however, are in pursuit. Meanwhile, Usopp and Franky meet, and Franky's past is revealed. It also becomes known that Franky holds the secret to a weapon called Pluton. Because the government is seeking this weapon, CP9 also captures Franky and Usopp.