Cross His Name Off the List

Lupin and Fujiko are enjoying a nice day together. Fujiko asks Lupin to steal an expensive painting. Learning Fujiko is the reward, Lupin jumps at the job. After Lupin runs off with the painting, he learns its a fake and finds himself in a bind when he learns Fujiko double crossed him and is working for the owner of the painting. After finding out the man once conned him years before, Lupin begins to wonder what this man plans to do. Lupin's suspicions get the best of him, and after a couple of failed attempts, he breaks into the man's house. What does this man wish to do, and what is Fujiko up to?