The musing smile lingered again about the boy’s lips.

‘You’re tired out, old man,’ went on the American.  ’I shouldn’t have waked you.  Good-night.’

The other stopped him from rising by catching his arm with his hand.  ‘Do you mind,’ said Dick, his eyes opening wide, ’just staying here until I go to sleep? . . .  There are all sorts of wild things going through my head to-night . . . waves pounding, pounding, pounding.  It never stops, Selwyn. . . .  And I seem to hear shouts a long way off—­like smugglers landing their stuff in the dark.  I’m an awful idiot to talk like this, old boy, but I’ve lost my courage a bit.’

And so for nearly half-an-hour the American remained watching by the lad as sleep hovered about and gradually settled on him.

As Selwyn quietly stole from the room the City’s clocks were striking three.

II.

It was after nine o’clock when Selwyn woke from a deep, refreshing sleep.  Hurrying into the other room, he found no sign of his guests.

‘When did these gentlemen leave?’ he asked of his servant, who had answered his ring.

’It must have been about six o’clock, sir.  I heard the door open and shut then.’

‘Why didn’t you call me?’

’I wasn’t wanting to disturb you, sir.  It’s the first good sleep you’ve had for a long time.’

It was true.  The sinking of himself into the personality of another man had released the fetters of his intensive egotism.  For a whole night he had forgotten, or at least neglected, his world-mission in simple solicitude for one who had fallen by the wayside.

After the stimulus of a cold shower and a hearty breakfast, he resumed his crusade against the entrenched forces of Ignorance, but in spite of the utmost effort in concentration, the memory of the lonely figure by the Thames intruded constantly on his mind.  It was not only that Dick was the brother of Elise—­although Selwyn’s longing for her had become a dull pain that was never completely buried beneath his thoughts; nor was it merely the unconscious charm possessed by the boy, a charm that seized on the very heart-strings.  To the American the real cruelty of the thing lay in the existence of a Society that could first debase so fine a creature, and then make no effort to retrieve or to atone for its crime.

Putting aside the day’s work he had planned, he flung his mind into the arena of England’s social conditions.  Exerting to the full his gift of mental discipline, he rejected the promptings of prejudice and of sentiment, and brought his sense of analysis to bear on his subject with the cold, callous detachment of a scientist studying some cosmic phenomenon.

For more than an hour his brain skirmished for an opening, until, spreading the blank sheets of paper before him, he wrote:  ’THE ISLAND OF DARKNESS.’  Tilting his chair back, he surveyed the title critically.