It may have been some look upon our faces – I have no doubt that the evil grin of my companion had widened at the sight – but, however that may be, Challenger's hand flew up to his head and he became conscious of his condition. The next instant he had sprung out of his chair, seized the inventor by the throat, and had hurled him to the ground. Knowing Challenger's immense strength I was convinced that the man would be killed.

'For God's sake be careful. If you kill him we can never get matters right again!' I cried.

That argument prevailed. Even in his maddest moments Challenger was always open to reason. He sprang up from the floor, dragging the trembling inventor with him. 'I give you five minutes,' he panted in his fury. 'If in five minutes I am not as I was, I will choke the life out of your wretched little body.'

Challenger in a fury was not a safe person to argue with. The bravest man might shrink from him, and there were no signs that Mr. Nemor was a particularly brave man. On the contrary, those blotches and warts upon his face had suddenly become much more conspicuous as the face behind them changed from the colour of putty, which was normal, to that of a fish's belly. His limbs were shaking and he could hardly articulate.

'Really, Professor!' he babbled, with his hand to his throat, 'this violence is quite unnecessary. Surely a harmless joke may pass among friends. It was my wish to demonstrate the powers of the machine. I had imagined that you wanted a full demonstration. No offence, I assure you. Professor, none in the world!'

For answer Challenger climbed back into the chair.

'You will keep your eye upon him, Malone. Do not permit any liberties.'