At the appointed hour, with the assistant manager holding a stopwatch and a storeful of patrons to cheer her on, she was given a shopping cart and five minutes to fill it with anything she wanted from the shelves.

I had little clue that I was being carefully monitored by the CCTV.

She was frankly disappointed. For some reason she had thought to discover a burglar of one or another accepted type—either a dashing cracksman in full-blown evening dress, lithe, polished, pantherish, or a common yegg, a red-eyed, unshaven burly brute in the rags and tatters of a tramp.

Complaints have risen in particular from passengers changing trains, who have observed little or no improvement in their ability to navigate between the station's 13 platforms.