The cops have cracked the Nicholas Roerich Museum case! You may recall two paintings were stolen off the walls of that museum in June. Denis Ryjenko and his girlfriend, Natella Croussouloudis, have been busted trying to sell one of the paintings, The Himalayas, to an undercover cop. (The other painting, Talung Monastery, had been returned by mail to the museum.) Ryjenko and Croussouloudis apparently needed the money — they owe $7,500 back rent and their lights and gas had been shut off. The most recent figures show art theft to be a $6 billion business internationally — though a few big scores could raise the number dramatically. The couple in question were only looking for $40,000 — but The Himalayas, a pencil sketch, is only valued at $20,000. Maybe that was their mistake — they got greedy! They could have moved it more easily at the Washington Square Art Show.