‘He called here the day before yesterday, in the evening, to speak to me about his marriage with my sister. They have been engaged for some time, you must know. While he was here I received a note from my sister herself, pressing me to come and speak to her at once outside the Palace. I went, leaving my brother-in-law to wait here during my absence. My sister, I found, merely wished to urge me not to object to any proposal made by her betrothed. On my return I found Severinski yawning and apparently bored to death in my absence. I asked him, and he assured me no one had come near the room while I was away.’

I could scarcely resist smiling as the whole intrigue, so simple, and yet so consummately successful, lay bared to my perception. My whole anxiety now was to keep the worthy but stupid Zeiss ignorant of the transaction in which he had been an unwitting accomplice.

I brought him away from the Palace with me, so as to leave him no opportunity of warning Severinski, and we proceeded together to the Russian’s quarters. I flatter myself that the professor of the Military College was not a little disconcerted when he saw his dupe followed into the room by an Inspector of the Berlin Police.

I explained my position in such a manner as to let Severinski see that I knew everything, without enlightening the other man.

‘The day before yesterday Herr Zeiss left you alone in his room in the Palace. You took the opportunity to send a telegram, the terms of which are known to me, over the Emperor’s private wire. For this offence you and he are liable to severe punishment. What I now have to propose to you is to make a confession which will have the effect of exonerating every one except yourself. If you do this, I think I can promise you that you shall suffer no penalty beyond, of course, the loss of your post in the Military College.’

Severinski gave me a glance of intelligence.

‘You do not require me to denounce anybody else?’ he inquired significantly.

‘I do not require you to confess what is obvious to every one,’ I returned with equal significance.

Poor Zeiss followed this exchange with an air of bewilderment. It was evident that the discovery of the other’s guilt had caused a shock to his confiding nature, and he was still trying to reconcile the Russian’s prompt surrender to me with his previous stupidity on questions of electrical science, when I summarily dismissed him from further share in the interview.

As soon as we were by ourselves Severinski spoke out boldly enough.