“My Gawd!” he shivered.  “Look!  Dar it is again!”

He fell to pattering in a tongue unknown to me—­charms, spells, undoubtedly, to exorcise the devils that had hold of him.  I followed the direction of his gaze, and myself cried out.

The doctor’s laboratory stood in plain sight between the two columns of steam blown straight upward through the stillness of the evening.  It seemed bursting with light.  Every little crack leaked it in generous streams, while the main illumination appeared fairly to bulge the walls outward.  This was in itself nothing extraordinary, and indicated only the activity of those within, but while I looked an irregular patch of incandescence suddenly splashed the cliff opposite.  For a single instant the very substance of the rock glowed white hot; then from the spot a shower of spiteful flakes shot as from a pyrotechnic, and the light was blotted out as suddenly as it came.  At the same moment it appeared at another point, exhibited the same phenomena, died, flashed out at still a third place, and so was repeated here and there with bewildering rapidity until the walls of the valley crackled and spat sparks.  Abruptly the darkness fell.

As abruptly it was broken again by a similar exhibition; only this time the fire was blue.  Blue was followed by purple, purple by red.  Then ensued the briefest possible pause, in which a figure moved across the bars of light escaping through the chinks of the laboratory, and then the whole valley blazed with patches of vari-coloured fire.  It was not a reflection:  it was actual physical conflagration of the solid rock, in irregular areas.  Some of the fire shapes were most fantastic.  And with the unexpectedness of a bursting shell the surface of the ground before our feet crackled into a ghastly blue flame.

The Nigger uttered a cry in his throat and disappeared.  I felt a sharp breath on my neck, an ejaculation of surprise at my very ear.  It was startling enough to scare the soul out of a man, but I held fast and was just about to step forward, when my collar was twisted tight from behind.  I raised both hands, felt steel, and knew that I was in the grasp of Handy Solomon’s claw.

The sailor had me foul.  I did my best to twist around, to unbutton the collar, but in vain.  I felt my wind leaving me, the ghastly blue light was shot with red.  Distinctly I heard the man’s sharp intaken breath as some new phenomenon met his eye, and his great oath as he swore.  “By the mother of God!” he cried, “it’s the devil.”

Then I was jerked off my feet, and the next I knew I was lying on my back, very wet, on the beach; the day was breaking, and the men, quite sober, were talking vehemently.