Ravenshaw raised his head to reply, then stood mute, in a listening attitude.  Outside the window the sound of footsteps crunched the gravel walk, and approached the house.  Thalassa heard and listened too.  The crunching ceased, and there was a knock at the door.  Thalassa looked questioningly at Ravenshaw, who nodded in the direction of the door.

“Open it,” he said.  Thalassa hesitated.  His eyes sought the couch.  “Yes, in here,” said Ravenshaw understandingly.  “We shall want witnesses.”

Thalassa went to the door and opened it.

A man’s voice in the darkness asked for Dr. Ravenshaw, and the owner of the voice stepped quickly inside at Thalassa’s invitation.  The visitor peered at the tall figure in the unlighted passage.  “Is it you, Thalassa?” he said hesitatingly, and Thalassa recognized the voice of Austin Turold.  The voice went on:  “Tell me—­”

“In there.”  Thalassa jerked his head towards the gleam falling through the partly open surgery door.  “He wants you.”  He walked ahead and pushed the door open.  Austin Turold followed, but started back as he looked within.  Then he entered, his eyes dwelling on the shadowy outline on the couch in the corner.

“What has happened at Flint House, Ravenshaw?  Now—­to-night, I mean.”  He spoke shakily.  “There’s a story abroad of Thalassa having been seen carrying a figure through the churchtown and entering your house.  Has somebody fallen off the cliffs—­been drowned?  Is that it?” He stepped quickly across to the couch, and, looking down, as swiftly recoiled.  “What does this mean?” he hoarsely cried.

Ravenshaw did not speak.

“Miss Sisily fell over the cliffs by the Moon Rock,” said Thalassa.  “I went down for her, but it was too late.  She was drowned.”

Austin’s look sought Ravenshaw’s, who nodded in confirmation.

“More horror—­more misery,” whispered Austin.  A shudder ran through him.  “I do not understand,” he said simply.  “Thalassa?”

“It’s not for me to explain,” said Thalassa quickly.

“You then, Ravenshaw.”

Ravenshaw spoke slowly.

“They have been looking for the man who killed Robert Turold—­your brother.  Well, I am he.”

“You!” gasped Austin, in a choking voice.  “What do you mean?  I do not understand you.  My son has been arrested.”

“He has been arrested wrongly, then.  It is I—­I alone am responsible.”

Austin groped for his glasses like a man suddenly enveloped in darkness.  His fingers closed on them and adjusted them on the bridge of his nose.  Through them he surveyed the man before him with close attention.

“Ravenshaw,” he said gravely, “either you are mad or I am.  Did not my sister call here to see you on the night my brother was killed, and did you not go with her to Flint House and break into my brother’s room?  How, then, could you have killed Robert?  Besides, I saw my son at Penzance to-day.  He tells me he is innocent, and that the murderer is a man whom Robert and Thalassa robbed and wounded on a lonely island thirty years ago, and left there for dead, as they thought.  What does it all mean?”