 Lupin(who is half asleep) receives a phone call from Fujiko that she s the first witness of a Scientist s Diamond Making robot, and told him to see it for himself. So he, Jigen, and Goemon did so, even though Lupin kept thinking he just dreamed. But by the time they go there, the Robot was taken by Gavotte, a dimwitted gangster who needs the robot as a present for his girlfriend, "Baby". Unfortunatly the robot only produces Icy Water and diamonds. So Gavotte gets his men to kidnap the Scientist and soon it becomes a series of failed exchanges between the robot and scientist, so Lupin and Gavotte agreed to do a swap site at an amusement park. But can the Robot be brought back to it s Diamond working order?