“Ooooh!” said Polly, peering furtively out the window. “What fun. It looks like a market researcher!” “Right,” said my mother in a very military tone. “Let’s see how long we can keep him before he runs out screaming. I’ll pretend to have mild dementia, and you can complain about your sciatica in German. We’ll try to beat our personal Market-Researcher Containment record of two hours and twelve minutes.”

