Death on a Pale Horse - By Donald Thomas Page 0,101

the Morning Post and with the envelope in his hand went over to his crowded and disreputable “chemical table.” There he struck a match, lit a Bunsen burner at low heat, filled a glass retort with water from a bottle and placed the vessel on the flame. He watched until the water began to bubble gently. A cloud of steam drifted from the nozzle of the retort. He held the unopened letter so that the warm vapour played gently upon the hardened wax. A moment later, the wax began to soften. Judging the exact point at which to ease open the envelope, he took a fine steel blade and prised the flap of paper from its pouch. He drew out a card with the message upon it, read it, and then handed it across the table to me.

You are quite right, of course. I have taken your advice and am returning to India. I shall pass what remains of my summer leave in the cool hills of Simla. My passage is booked on the P & O liner Himalaya at the end of next week. Whatever is still to be done in England, I believe you are the only man to do it. I regret only that my foolish attempt to intervene may have served to make your task more difficult.

I remain, sir,

Yours faithfully,

H P-W

“He has bitten the bullet, then!” I said as I passed the card back. Without replying, he took up a magnifying lens and began to examine the wax as it cooled and hardened again. After murmuring something to himself, he slapped his knee and turned to me.

“Excellent! Admirable! Putney-Wilson has done as I told him; I do believe they have fallen for it!”

“Fallen for what?”

“My dear fellow, I had rather counted upon Colonel Moran or one of his satraps intercepting any letter which came via the postal service to this address from Major Putney-Wilson—let alone from Samuel Dordona!”

“But that envelope has not been intercepted, surely? The seal was unbroken. Had the envelope been slit open at its edges?”

“No. A Scotland Yard amateur would recognise that at once.”

“What then? There are no broken fragments of wax, as there must be if a seal is removed. Do you mean that they have steamed it open as you have done?”

He shook his head.

“The wax seal has been replaced. Once it has been opened, it cannot be re-sealed with the original wax alone. It requires a new seal with a little extra wax on top of what was there before. To look convincing, the new seal must overlap the original wax imprint, however slightly. It is a serviceable method of deception—but for one thing: the old wax will have been heated twice and is therefore darker in colour; the new wax is melted only once and is therefore lighter. To those who know where to look—and how to look with an examining lens or a microscope—the slight discrepancy between the two layers betrays the secret interception. That discrepancy is here, as you may see if you care to borrow this glass. In other words, we are not the first people to read the contents of this note. Putney-Wilson has done as I told him. That is most, most gratifying, is it not?”

He handed me the magnifying glass and the envelope. As always, he was correct.

“How did you learn that trick?”

He smiled reminiscently.

“My investigation of the Maida Vale blackmail mystery, involving a fortune-teller and a private secretary to the Prince of Wales, pre-dates the happy occasion when you and I first made one another’s acquaintance. In the course of that earlier investigation, I was introduced to the ‘Black Chamber’ of the General Post Office at St. Martin’s-Le-Grand.”

“The Black Chamber?”

He smiled.

“My dear Watson! Every government has such an office, of necessity. In our case it is a room where, for reasons of state, letters posted by suspected persons are opened by government officers on the authority of the Attorney-General and under the direction of an Official Examiner. They are scrutinised and then resealed and put into a special basket for the evening deliveries of the same day. The Examiner forwards a report to the Treasury Solicitor who normally requests the interception. Never make the mistake, Watson, of believing that a letter addressed to you has not been read by someone else first. Especially if it arrives by the evening post, rather than in the morning.”

I handed back the lens and the envelope.

“Then our adversaries know that Major Putney-Wilson has withdrawn from the