Long after they had clambered into the car, the creature with the cloven face continued to leer down upon the smoke-stung crowd below.  Then at last he said in a silken voice and with a smile of final satisfaction: 

“By the way, I fear I am very absent minded.  There is one man specially whom, somehow, I always forget.  I always leave him lying about.  Once I mislaid him on the Cross of St. Paul’s.  So silly of me; and now I’ve forgotten him in one of those little cells where your fire is burning.  Very unfortunate—­especially for him.”  And nodding genially, he climbed into his flying ship.

MacIan stood motionless for two minutes, and then rushed down one of the suffocating corridors till he found the flames.  Turnbull looked once at Madeleine, and followed.

* * *

MacIan, with singed hair, smoking garments, and smarting hands and face, had already broken far enough through the first barriers of burning timber to come within cry of the cells he had once known.  It was impossible, however, to see the spot where the old man lay dead or alive; not now through darkness, but through scorching and aching light.  The site of the old half-wit’s cell was now the heart of a standing forest of fire—­the flames as thick and yellow as a cornfield.  Their incessant shrieking and crackling was like a mob shouting against an orator.  Yet through all that deafening density MacIan thought he heard a small and separate sound.  When he heard it he rushed forward as if to plunge into that furnace, but Turnbull arrested him by an elbow.

“Let me go!” cried Evan, in agony; “it’s the poor old beggar’s voice—­he’s still alive, and shouting for help.”

“Listen!” said Turnbull, and lifted one finger from his clenched hand.

“Or else he is shrieking with pain,” protested MacIan.  “I will not endure it.”

“Listen!” repeated Turnbull, grimly.  “Did you ever hear anyone shout for help or shriek with pain in that voice?”

The small shrill sounds which came through the crash of the conflagration were indeed of an odd sort, and MacIan turned a face of puzzled inquiry to his companion.

“He is singing,” said Turnbull, simply.

A remaining rampart fell, crushing the fire, and through the diminished din of it the voice of the little old lunatic came clearer.  In the heart of that white-hot hell he was singing like a bird.  What he was singing it was not very easy to follow, but it seemed to be something about playing in the golden hay.

“Good Lord!” cried Turnbull, bitterly, “there seem to be some advantages in really being an idiot.”  Then advancing to the fringe of the fire he called out on chance to the invisible singer:  “Can you come out?  Are you cut off?”

“God help us all!” said MacIan, with a shudder; “he’s laughing now.”

At whatever stage of being burned alive the invisible now found himself, he was now shaking out peals of silvery and hilarious laughter.  As he listened, MacIan’s two eyes began to glow, as if a strange thought had come into his head.