This story deals with the little-known problem of fakes in the booming market for sculpture by Alexander Calder. Four prominent American art dealers were suing a London dealer and a collector, claiming that a Calder mobile they bought from the collector through the dealer was a fake. The leading expert on the artist's works, Klaus Perls, agreed it was a fake, but a judge disagreed and ruled the work genuine. This decision shocked the art world, as a judge with no background in art overruled the expert. Since Perls retirement, Calder's grandson, Alexander Rower, is the official expert on his grandfather's work, as is producing the authoritative catalogue raisonne. This means he has sole authority to bestow the stamp of authenticity. Many dealers and collectors are distressed that Rower has rejected about 80 works as fakes without any real explanation. People who are knowledgeable think that Rower, who was 13 when his grandfather died and has no training in art history, isn't qualified to make such judgments.