“I can’t see how we’re going to get a verdict of murder against this man, although it is as plain as daylight that he poisoned Mills and was responsible for the bomb outrage. But you can’t hang a man on suspicion, even though the suspicion is not open to doubt. How did he kill Mills, do you think?”

“Mills had a cold,” said Dick. “He had been coughing all the way up in the car, and had asked Balder to close the window of the room. Balder obviously closed, or nearly closed the window, and probably slipped a cyanide tablet to the man, telling him it was good for his cold. It was a fairly natural thing for Mills to take and swallow the tablet, and that, I am sure, is what happened. We made a search of Balder’s house at Slough, and found a duplicate set of keys, including one to Elk’s safe. Balder got there early in the morning and planted the bomb, knowing that Elk and I would be opening the bags that morning.”

“And helped Hagn to escape,” said the Public Prosecutor.

“That was much more simple,” explained Dick. “I gather that the inspector who was seen walking out at half-past-two was Hagn. When Balder went into the cell to keep the man company, he must have been dressed underneath in the police uniform, and have carried the necessary handcuffs and pass-keys with him. He was not searched—a fact for which I am as much responsible as Elk. The chief danger we had to fear from Balder came from his closeness to us, and his ability to communicate immediately to his chief every movement which we made. His name is Kramer, and he is by birth a Lithuanian. He was expelled from Germany at the age of eighteen for his revolutionary activities, and came to this country two years later, where he joined the police. At what time he came into contact with the Frogs I do not know, but it is fairly clear, from evidence we have obtained, that the man has been engaged in various illegal operations for many years past. I’m afraid you are right about Balder: it will be immensely difficult to get a conviction until we have caught Frog himself.”

“And will you catch the Frog, do you think?”

Dick Gordon smiled cryptically.

No fresh news had come about the murder of Maitland and his sister, and he seized the opportunity which the lull gave to him. Ella Bennett was in the vegetable garden, engaged in the prosaic task of digging potatoes when he appeared, and she came running toward him, stripping her leather gloves.

“This is a splendid surprise,” she said, and flushed at the consciousness of her own enthusiasm. “Poor man, you must be having a terrible time! I saw the newspaper this morning. Isn’t it dreadful about poor Mr. Maitland? He was here yesterday morning.”

He nodded.

“Is it true that Mr. Johnson has been left the whole of Maitland’s money? Isn’t that splendid!”