The Tunnel of Bones (Double Detectives)

Paris: city of light, catacombs, pastries…and art thieves? When Cody and Otis Chandler, their father, and their cousin Rae journey to France, they discover that there's a crime wave going on: hundreds of paintings have been stolen and replaced by forgeries. When the thief snatches their dad's painting, the twins can't resist getting involved. Will they find out the truth before it's too late? The ending involves a chase scene through the Paris catacombs--plenty of dead ends, skulls, danger, and…rats!