Putting together the first authorized exhibition in 14 years of works by the anonymous street artist Banksy required extensive planning, and a cover story to hide its secret until it opened, unannounced, in Glasgow last summer. Correspondent Seth Doane explores the art and the mysteries of Banksy’s world, including the continued speculation about the artist’s true identity, a closely-held secret for decades. [An earlier version of this story was broadcast August 13, 2023.]