Mrs. Thatcher's London is bristling with the newly rich bankers, and property developers who have declared the city their personal playground. But on tiny Jerusalem Lane, time seems not so much to have stood still as to have slipped backwards. Its shabby houses are home to a clutch of elderly emigres, refugees from a once war-torn Europe who are still fighting ancient political battles, the Trotskyites thumping their canes in fury, the Leninists bellowing into the Anarchists' hearing-aids. To many outsiders, the Lane's enmities look like some quaint geezers' hobby, a louder version of canasta. But then the geezers start dying.