“He’s ill . . . fainted or something,” he gasped, and Elk sprang past him, along the corridor into the guard-room. Mills half sat, half lay, against the wall. His eyes were closed, his face was ashen. Dick bent over the prisoner and laid him flat on the ground. Then he stooped and smelt. “Cyanide of potassium,” he said. “The man is dead.” That morning Mills had been stripped to the skin and every article of clothing searched thoroughly and well. As an additional precaution his pockets had been sewn up. To the two detectives who accompanied him in the car he had spoken hopefully of his forthcoming departure to Canada. None but police officers had touched him, and he had had no communication with any outsider. The first thing that Dick Gordon noticed was the window, which Balder said he had shut. It was open some six inches at the bottom. “Yes, sir, I’m sure I shut it,” said the clerk emphatically. “Sergeant Jeller saw me.” The sergeant was also under that impression. Dick lifted the window higher and looked out. Four horizontal bars traversed the brickwork, but, by craning his head, he saw that, a foot away from the window and attached to the wall, was a long steel ladder running from the roof (as he guessed) to the ground. The room was on the third floor, and beneath was a patch of shrub-filled gardens. Beyond that, high railings. “What are those gardens?” he asked, pointing to the space on the other side of the railings. “They belong to Onslow Gardens,” said Elk. “Onslow Gardens?” said Dick thoughtfully. “Wasn’t it from Onslow Gardens that the Frogs tried to shoot me?” Elk shook his head helplessly. “What do you suggest. Captain Gordon?” “I don’t know what to suggest,” admitted Dick. “It doesn’t seem an intelligent theory that somebody climbed the ladder and handed poison to Mills—less acceptable, that he would be willing to take the dose. There is the fact. Balder swears that the window was shut, and now the window is open. You can trust Balder?” Elk nodded. The divisional surgeon came soon after, and, as Dick had expected, pronounced life extinct, and supported the view that cyanide was the cause. “Cyanide has a peculiar odour,” he said. “I don’t think there’s any doubt at all that the man was killed, either by poison administered from outside, or by poison taken voluntarily by himself.” After the body had been removed. Elk accompanied Dick Gordon to his Whitehall office. “I have never been frightened in my life,” said Elk, “but these Frogs are now on top of me! Here is a man killed practically under our eyes! He was guarded, he was never let out of our sight, except for the few minutes he was in that room, and yet the Frog can reach him—it’s frightening, Captain Gordon.” Dick unlocked the door of his office and ushered Elk into the cosy interior.