At first glance Alfred and Sylvia Lawrie were hardly the sort of people one would have called intimidating. Alfred was in his late 70s, tall and vague, one of those elderly men who stay long and skinny in the arms and legs, but put on weight in the middle. His beard was white and haphazard, like a bum’s whiskers. Sylvia, short and stout as a robin, had a sharp beak of a nose and the ruddy face of a drinker, but her blue eyes sparkled with impish good humor, and she had an infectious, braying laugh.