“You must admit that many of your actions are incomprehensible,” Hamel replied slowly.  “There are things here which I do not understand—­which certainly require explanation.”

“Still, why do you make them your business?” Mr. Fentolin persisted.  “If indeed the course which I steer is a harmless one,” he continued, with a strange new glitter in his eyes, “then you are an impertinent stranger to whom my doors cannot any longer be open.  If you have taken advantage of my hospitality to spy upon me and my actions, if indeed you have a mission here, then you can carry it with you down into hell!”

“I understand that you are threatening me?” Hamel murmured.

Mr. Fentolin smiled.

“Scarcely that, my young friend.  I am not quite the obvious sort of villain who flourishes revolvers and lures his victims into secret chambers.  These words to you are simply words of warning.  I am not like other men, neither am I used to being crossed.  When I am crossed, I am dangerous.  Leave here, if you will, in safety, and mind your own affairs; but if you show one particle of curiosity as to mine, if you interfere in matters which concern me and me only, remember that you are encircled by powers which are entirely ruthless, absolutely omnipotent.  You can walk back to the Tower to-night and remember that there isn’t a step you take which might not be your last if I willed it, and never a soul the wiser.  There’s a very hungry little mother here who takes her victims and holds them tight.  You can hear her calling to you now.  Listen!”

He held up his finger.  The tide had turned, and through the half-open window came the low thunder of the waves.

“You decline to share my evening,” Mr. Fentolin concluded.  “Let it be so.  Go your own way, Hamel, only take care that your way does not cross mine.”

He backed his chair slowly and pressed the bell.  Hamel felt himself dismissed.  He passed out into the hall.  The door of the drawing-room stood open, and he heard the sound of Mrs. Fentolin’s thin voice singing some little French song.  He hesitated and then stepped in.  With one hand she beckoned him to her, continuing to play all the time.  He stepped over to her side.

“I come to make my adieux,” he whispered, with a glance towards the door.

“You are leaving, then?” she asked quickly.

He nodded.

“Mr. Fentolin is in a strange humour,” she went on, a moment later, after she had struck the final chords of her song.  “There are things going on around us which no one can understand.  I think that one of his schemes has miscarried; he has gone too far.  He suspects you; I cannot tell you why or how.  If only you would go away!”

“What about Esther?” he asked quietly.

“You must leave her,” she cried, with a little catch in her throat.  “Gerald has broken away.  Esther and I must carry still the burden.”