It was towards the close of an unusually long day’s work and Major Thomson sighed with relief as he realised that at last his anteroom was empty. He lit a cigarette and stretched himself in his chair. He had been interviewed by all manner of people, had listened to dozens of suspicious stories. His work had been intricate and at times full of detail. On the whole, a good day’s work, he decided, and he had been warmly thanked over the wires by a Brigadier-General at Harwich for his arrest and exposure of a man who had in his possession a very wonderful plan of the Felixstowe land defences. He lit a cigarette and glanced at his watch. Just then the door was hurriedly opened. Ambrose came in without even the usual ceremony of knocking. He held a worn piece of paper in his hand. There was a triumphant ring in his tone as he looked up from it towards his chief. “I’ve done it, sir!” he exclaimed. “Stumbled across it quite by accident. I’ve got the whole code. It’s based upon the leading articles in the Times of certain dates. Here’s this last message--‘Leave London June 4th. Have flares midnight Buckingham Palace, St. Paul’s steps, gardens in front of Savoy. Your last report received.’” “‘Leave London June 4th,’” Thomson repeated, glancing at his calendar,--“to-day! ‘Have flares,’--Zeppelins, Ambrose!” The clerk nodded. “I thought of them at once, sir,” he agreed. “That’s a very plain and distinct warning in a remarkably complicated code, and it’s addressed--to Sir Alfred Anselman.” A smouldering light flashed in Thomson’s eyes. “Ambrose,” he declared, “you’re a brick. I sha’n’t forget this. Just find out at once if the Chief’s in his room, please.” There followed half an hour of breathless happenings. From the Chief’s room Thomson hurried over to the Admiralty. Here he was taken by one of the men whom he had called to see, on to the flat roof, and they stood there, facing eastwards. Twilight was falling and there was scarcely a breath of air. “It’s a perfect night,” the official remarked. “If they start at the right time, they’ll get here before any one can see them. All the same, we’re warning the whole coast, and our gun-stations will be served all night.” “Shall we have a chance, do you think, of hitting any of them?” Thomson asked. The sailor winked. “There are a couple of gun-stations I know of not far from here,” he said. “I tell you they’ve got armament there which will make our friends tear their hair’ shells that burst in the air, mind, too, which you needn’t mind letting ‘em have as quick as we can fire ‘em off. I shall try and get on to one of those stations myself at midnight.” “What time do you think they’d attack if they do get over?” The other took out his watch and considered the subject.