A famous painting was stolen from the Art Institute of Chicago. Frisky and Holly are called in to help the police. They search the building, and notice a smell that the police missed. While the police are searching, they go for a Chinese lunch and head to the field Museum. On the way, they find another clue. The police are notified, and the dogs visit the Field Museum. Here, one of the robbers tries to hurt Holly. On the way back to the Art Institute they find another clue.

The painting was left at the Art Institute, and the robbers will pick it up tonight. The police set up a stakeout at the Institute and wait. The thief arrives, but manages to get into the building without being detected. The police can't find him, and it looks like all is lost. Read the book to find out if our heroes can figure this out.