The Collector, an anonymous art dealer, has stolen 16 paintings from galleries around the world, and replaced each painting with a fake. Up until now, no one has found out. Meanwhile, these galleries have donated paintings to raise money for a good cause - the Great Art Auction of 34 world-famous paintings is going to be a magnificent occasion. The auctioneer has displayed the 34 paintings in the auction house. He has just finished work for the evening on the day before the auction when he receives an e-mail tip-off about the fake paintings. A reformed forger has heard a rumour that 16 of the paintings in the auction are fakes. The informant explains that four well-known gangs have produced copies for the Collector so he could steal the originals and replace them with the fakes. He explains that the fakes can be identified because each gang member signs their work with a personal symbol, such as a star, and that, although they are expert forgers, they do make some mistakes as they copy the originals. The word is that the Collector has supposedly paid GBP 100,000 for a perfect forgery and deducted GBP 10,000 per mistake. The auctioneer calls the police. An art crime detective tells him that she is aware of four possible collectors, and she faxes over a 'WANTED' poster of the four suspects. The police advise the auctioneer to work out which paintings are fakes, identify who painted each fake (by looking for each gang member's symbol), and then work out the fee paid for each forgery and how much the Collector paid to each gang. The detective has bank statements from their four suspects. Matching the fees paid to the gangs with the payments listed on these statements will help identify the culprit.