“I have told you already,” I said.  “So still a night I never remember on this Yorkshire moor.”

He laid one hand heavily on my shoulder.  “What did the poor boy say of me, whose brother I killed?” he asked.  “What words did we hear through the dripping darkness of the mist?”

“I won’t encourage you to think of them.  I refuse to repeat the words.”

He pointed over the northward parapet.

“It doesn’t matter whether you accept or refuse,” he said, “I hear the boy at this moment—­there!”

He repeated the horrid words—­marking the pauses in the utterance of them with his finger, as if they were sounds that he heard: 

“Assassin!  Assassin! where are you?”

“Good God!” I cried.  “You don’t mean that you really hear the voice?”

“Do you hear what I say?  I hear the boy as plainly as you hear me.  The voice screams at me through the clear moonlight, as it screamed at me through the sea-fog.  Again and again.  It’s all round the house. That way now, where the light just touches on the tops of the heather.  Tell the servants to have the horses ready the first thing in the morning.  We leave Vange Abbey to-morrow.”

These were wild words.  If he had spoken them wildly, I might have shared the butler’s conclusion that his mind was deranged.  There was no undue vehemence in his voice or his manner.  He spoke with a melancholy resignation—­he seemed like a prisoner submitting to a sentence that he had deserved.  Remembering the cases of men suffering from nervous disease who had been haunted by apparitions, I asked if he saw any imaginary figure under the form of a boy.

“I see nothing,” he said; “I only hear.  Look yourself.  It is in the last degree improbable—­but let us make sure that nobody has followed me from Boulogne, and is playing me a trick.”

We made the circuit of the Belvidere.  On its eastward side the house wall was built against one of the towers of the old Ab bey.  On the westward side, the ground sloped steeply down to a deep pool or tarn.  Northward and southward, there was nothing to be seen but the open moor.  Look where I might, with the moonlight to make the view plain to me, the solitude was as void of any living creature as if we had been surrounded by the awful dead world of the moon.

“Was it the boy’s voice that you heard on the voyage across the Channel?” I asked.

“Yes, I heard it for the first time—­down in the engine-room; rising and falling, rising and falling, like the sound of the engines themselves.”

“And when did you hear it again?”