“How shall we make a start here?” asked Ellery, rather forlornly, as they stood at the corner of Cockspur Street, overlooking Trafalgar Square. At the foot of the Nelson Column stood the usual curious—and incurious—crowd listening to some orator descanting on the rights—or wrongs—of labour. “Follow the old precept, of course,” said Joan promptly. “Ask a policeman. There seem to be plenty about.” Ellery went up to the nearest and began to explain his business. He was speedily referred to the sergeant, who was standing at the edge of the crowd, eyeing the little knot of speakers on the plinth, as if he was meditating a possible arrest. “He’ll know who was on duty on Tuesday night. I wasn’t,” said the constable. The sergeant was communicative. First, he bade them wait a few minutes while he listened to what the speaker, then on her feet—for it was a woman—was saying. What she said appeared to give him satisfaction; for he smiled happily, as he entered a note in his book. Then the speech became more commonplace, and the sergeant, bidding a constable take notes while he was busy, signified his willingness to attend to Joan and Ellery. But, before they could tell him of their concerns, they had to listen awhile to his, which related mainly to the iniquity of allowing seditious meetings to be held openly in Trafalgar Square. “They tell us to take it all down, they do—every word; and then they do nothing. They shove it away in some pigeon-hole or other.” “They” were presumably the powers that ruled, at the Home Office, over the doings of the Metropolitan Police. “What I say is, What’s the police for, if it isn’t to stop this kind of thing?” He jerked his thumb in the direction of the plinth. “But you make an arrest sometimes, don’t you?” Joan asked. “Once in a blue moon, maybe. But even then, more often than not the Home Secretary lets ’em go. Disgusting, I call it, and demoralising for the country. If I had my way . . .” He had his way for a few minutes, as far as words went, and then, as the reward of patient listening, he let Ellery have his say. But he was not helpful. “Yes, I know who was on duty here that night. There was Bill Adams and Tom Short down by Whitehall, and there was George Mulligan patrolling up there by the Gallery. But it’s a hundred to one against any of them having noticed your man. Adams is on duty here, and the other two will be along at the station. You can have a word with Adams now, and I’ll take you along to the station myself in a few minutes. They’re just finishing up there.” He jerked a thumb in the direction of the plinth. Adams, a tall, fat policeman, who kept patting himself on the stomach while he talked, had seen nothing of Walter Brooklyn, whose photograph Ellery showed him. “Lord bless you, if I was to notice everybody I should have a job on,” was his comment, clearly showing his view of the hopelessness of their search. Discouraged, they left him, and went to the station with the sergeant.