The life of 20th-century artist Nicolas de Staël has been mythologized ever since he ended it by jumping from his studio age 41, at the height of his career, in 1955. At times, experts say the myth has overshadowed more than 1,000 paintings he created in a span of just 15 years. De Staël’s work has been a multi-year obsession of Patrick Quéré, an eccentric American, who claims that he holds a key to seeing the tragic artist’s output in a new light. Quéré’s preoccupation began with a small