Pickpocket in a Pushchair

Lefty and Righty have just run to show me something, both of them filled with concern.

"Mr J took a marble from the Art Gallery!" Lefty says. 

"What do you mean?"

"He took one of the marbles for sale in the shop!" Righty replies. He holds out a creamy white marble, with blue, red, and yellow streaks. 

I look at Mr J, and hold up the marble. "Mr J, where did you find this?"

"A’ the Awt Gawry," he responds happily. 

After a brief explanation about not taking things that aren’t ours, I put the marble away to be returned as soon as we can. When Mr J took the Terry’s Chocolate Orange from the stationer’s shop, at least we were able to return it within five minutes. The marble has been in his pocket until laundry day yesterday!