Alice spun on her heel to face the stranger. She was sure the alley had been empty - how had she missed him?

Her violently green eyes - the only real splash of colour on her - narrowed, her fingers flexing as they inched towards a pocket.

"You're not one of the sentry," she accused sharply, looking him over head to toe. He didn't seem dangerous, but then, neither had Doctor Bumby. Some people were very good, indeed, at seeming.