Who's Got the Lady?

Parnell is an art dealer who plans to steal an important picture from his own London art gallery. During a ceremony to unveil The Patrician Lady (a masterpiece on temporary loan) gun shots and an explosion suggest a robbery. Afterwards, surprisingly, The Patrician Lady seems to be unharmed, but then Parnell finds the name 'Zarchetti' stamped on the back of the canvas, suggesting the picture is a fake. With the original under suspicion, Parnell plans that his artist girlfrend will then forge copies of the painting, which he can sell to several of his collectors who will each pay a good price for what appears to be the real masterpiece. But something goes wrong with the plan...