Essenden nodded and handed over his hat and coat. In exchange, he received one solitary letter, and the handwriting on the envelope was so familiar that he carried it to his study to open behind a locked door. The letter contained in the envelope was not so surprising to him as it would have been a month before:
Have a look at the safe behind the dummy row in your bookcase.
And underneath were the replicas of the two drawings that he had seen before.
Essenden struck a match and watched the paper curl and blacken in an ashtray. Then, with a perfectly impassive fatalism, he went to the bookcase and slid back the panel which on one shelf replaced a row of books. He had no anxiety about any of the papers there, for since the first burglary he had transferred every important document in his house to a safer place.
He opened the safe and looked at the notebook he had lost in Paris.
Thoughtfully he flicked through the pages.
Every entry had been decoded, and the interpretation written neatly in between the lines.
Essenden studied the book for some minutes; and then he dropped it into his pocket and began to pace the room with short bustling strides.
The notebook had not been in the safe when he arrived back from Paris that afternoon. He knew that, for he had deposited some correspondence there before he left again to interview the commissioner. And yet, to be delivered that night, the letter which told him to look in the safe must have been posted early that morning. And early that morning Jill Trelawney and the Saint were in Paris — and the letter was post-marked in London. There was something terrifying about the ruthless assurance which emerged from the linking of those two facts.
A gentle knock on the door almost made Essenden jump out of his skin.