Maker's Mark

Why do a sleazy antique dealer and a wealthy collector suddenly become interested in an unknown artist named Jo Allison? Is it the mysterious goblet she used in three still life paintings? After her apartment is burglarized and she is followed and threatened, she discovers that the goblet may be a priceless artifact. Thieves follow her to Chicago in the home of wealthy blind woman who also owns one of the goblets the climax of the story takes place on the steps of the Art Institute of Chicago between the two roaring lions.