An inventor named Lewis White comes to see Johnny
Diamond. He tells him about an invention of his that made
him a lot of money. It’s a system that makes it impossible
to steal a painting from the wall of an art gallery. If anybody
tries to take a painting from the wall, steel doors slam down
to seal the gallery and there’s no escape from it. JD finds
out that Lewis was so sure of his invention that he promised
everybody one million pounds if a thief ever stole a painting
from their gallery. However, there’s been a case of a stolen
painting, and Lewis wants JD to help him. Together they go
to the art gallery. As soon as they arrive, JD spots something
and asks for a floor plan of the gallery