His arm with the revolver was upraised, his eyes unwavering. The informer saw determination in his gaze. A further word of alarm, and a bullet would pass through his brain.

For a few seconds he stood in sullen silence.

“All right!” he shouted to them at last. “It is nothing, comrades. I was mistaken. Leave us in peace.”

We heard a murmuring of discontent outside, and then the footsteps commenced to descend the steep uncarpeted stairs. As they did so, Hartwig dropped his weapon, saying:

“Now let us sit down and talk. I have several questions I wish to put to you. If you answer frankly, then I promise that I will not betray you to your comrades.”

“What do you mean by ‘frankly’?”

“I mean that you must tell me the exact truth.”

The man’s face grew dark; his brows contracted; he bit his finger-nails.

“What was the motive of the attempt you made upon the Grand Duke Nicholas and his daughter, and the gentleman here, Mr Trewinnard?”

“I don’t know,” he replied.