“Quite. Then he went on, and this is what he said: ‘You all have Formula “A.” You will go to your posts and from your directions you will prepare what is needful according to that formula, carrying out to the last detail the cipher instructions which each of you has received. As soon as the experiments relating to Formula “B” are completed, you will receive a summons in code. You will then assemble at the rendezvous given, and Formula “B,” with all instructions for its employment, will be entrusted to you. With Formula “A” you have the key. When Formula “B” is also complete you will have the lock for that key to fit; then the treasures of the world are yours. The annihilation of civilisation and of the human race is within our grasp. When the key has turned in the lock we only shall be left, and....’ Just then, Renata said, some one else cried out, ‘The door! The door!’ They pushed the screen away and pulled her in. She nearly fainted. When she revived a little, her father and Mr. Ember were trying to find out what she had heard. Fortunately for herself, she told me, at first it was all confusion. The only thing that stood out clearly was that shout at the end, but afterwards, when she was alone, it all came back. She said it was like a photographic plate developing, hazy at first, and then everything getting clearer and sharper until each detail came out. She repeated the whole thing as if it were a lesson.” “Wait,” said Henry. “My head’s going round. I want to sort things out.” Jane waited. She had been prepared for Henry to be impressed or incredulous. What took her by surprise was the puzzled note in his voice. “Lord, what a mix-up!” she heard him say. Then he addressed her again. “Did you ever play ‘Russian Scandal,’ Jane?” he said. “Yes, of course. But if you had heard Renata—the sort of queer mechanical way she spoke, exactly like a gramophone record—why, the words weren’t words she’d have used, and all that about Formula ‘A’—do you think that’s the sort of thing that a schoolgirl makes up?” “No,” said Henry unexpectedly. “I think it is quite possible that she overheard something about Formula ‘A,’ and I’d give a good deal to know just what she did hear.” “I’ve told you what she heard,” said Jane. “Jimmy always said I had a photographic memory, and I said the whole thing over to myself until I had it by heart. You see, I didn’t dare to write it down.” “Can you say it again?” said Henry. “I’d like to get it down in black and white, and have a look at it. At present it makes me feel giddy.” “You mustn’t write it down,” said Jane breathlessly. “Oh, you mustn’t, Henry! It’s not safe.” Henry turned on his torch, propped it against the wall, and produced a notebook and a pencil. The cold, narrow beam of light showed his knee, the white paper, a pencil with a silver ring, and Henry’s large, brown hand. “He has a _horribly_ determined hand,” thought Jane.