‘Who the deuce are you?’ I asked.

Then, understanding that it was my uninvited visitor, with scant ceremony I drew myself away from him.  By the light which was streaming through the laboratory door I saw that Woodville was lying close beside me,—­stark and still.

‘Is he dead?’ I cried.  ’Percy.—­speak, man!—­it’s not so bad with you as that!’

But it was pretty bad,—­so bad that, as I bent down and looked at him, my heart beat uncomfortably fast lest it was as bad as it could be.  His heart seemed still,—­the vapour took effect directly on the cardiac centres.  To revive their action and that instantly, was indispensable.  Yet my brain was in such a whirl that I could not even think of how to set about beginning.  Had I been alone, it is more than probable Woodville would have died.  As I stared at him, senselessly, aimlessly, the stranger, passing his arms beneath his body, extended himself at full length upon his motionless form.  Putting his lips to Percy’s, he seemed to be pumping life from his own body into the unconscious man’s.  As I gazed bewildered, surprised, presently there came a movement of Percy’s body.  His limbs twitched, as if he was in pain.  By degrees, the motions became convulsive,—­till on a sudden he bestirred himself to such effect that the stranger was rolled right off him.  I bent down,—­to find that the young gentleman’s condition still seemed very far from satisfactory.  There was a rigidity about the muscles of his face, a clamminess about his skin, a disagreeable suggestiveness about the way in which his teeth and the whites of his eyes were exposed, which was uncomfortable to contemplate.

The stranger must have seen what was passing through my mind,—­not a very difficult thing to see.  Pointing to the recumbent Percy, he said, with that queer foreign twang of his, which, whatever it had seemed like in the morning, sounded musical enough just then.

‘All will be well with him.’

‘I am not so sure.’

The stranger did not deign to answer.  He was kneeling on one side of the victim of modern science, I on the other.  Passing his hand to and fro in front of the unconscious countenance, as if by magic all semblance of discomfort vanished from Percy’s features, and, to all appearances, he was placidly asleep.

‘Have you hypnotised him?’

‘What does it matter?’

If it was a case of hypnotism, it was very neatly done.  The conditions were both unusual and trying, the effect produced seemed all that could be desired,—­the change brought about in half a dozen seconds was quite remarkable.  I began to be aware of a feeling of quasi-respect for Paul Lessingham’s friend.  His morals might be peculiar, and manners he might have none, but in this case, at any rate, the end seemed to have justified the means.  He went on.

’He sleeps.  When he awakes he will remember nothing that has been.  Leave him,—­the night is warm,—­all will be well.’