‘The hour she woke?’ he asked presently, with such a vigorous ring in his tone that Wyndham rose to his feet astonished.

‘Two minutes ago.’

‘Hah!’ The Professor went back to his calculations. Presently a shout broke from him. ‘I see it now!’ he cried victoriously; ‘I see where the mistake lay! Fool that I was not to have seen it before! It was a miscalculation, but one easy to be rectified. An hour or two will do it. Here, help me up, Paul.’

‘But, Professor, it is impossible; you must rest; you——’

‘Not another moment, not one, I tell you!’ cried the Professor furiously. He lunged out of bed. ‘This thing must be seen to at once. What time can any man be sure of, that he should waste it? The discovery must be assured. And what time have I?’

He fell forward; he had fainted. Wyndham laid him back, and rushed frantically into the next room.

The girl was standing just where he had left her. But her arms were outstretched no longer; they were better employed—they were doing up her hair.

There was a glass on a wall opposite to him, and by this she was trying to bring herself back to as perfect a state of respectability as circumstances permitted her.

‘You must go,’ said Wyndham, ‘and at once. Do you hear—at once?’

And, indeed, it was imperative that she should be out of the house before the arrival of the doctor, for whom he was now about to go.