“Because I saw you.  I was standing outside, close to the house.”

“Why were you there?” she put in quickly.

He was slower in answering.  “I had gone to see your father—­about you.  I was standing there, thinking ... waiting, when the front door opened, and you and Thalassa came out.  I was surprised to see you, but it seemed to me an opportunity—­a final chance—­to speak to you again.  I started after you, Sisily, once more to ask you to consider my love for you, but you and Thalassa were swallowed up in the darkness of the moors before I could reach you.  I followed with the intention of overtaking you, but I got lost on the moors instead, and was wandering about in the blackness for nearly half an hour before I found my way back to Flint House again.”

“Could you not tell them—­the police—­that?” she asked, a little wistfully.

“It would be useless,” he solemnly replied.

“What do you mean?” she said breathlessly.

His rejoinder was a long time in coming.  When his set lips moved the words were barely audible.  “Because I would not be believed.  Because I went straight up the path to the house, determined to see your father before it grew later.  The front door was open, and the house seemed in complete darkness.  I entered, and went upstairs.  There was a light in your father’s study.  I found your father—­dead.”  He fixed care-worn eyes upon her.  “That story sounds incredible, even to you, doesn’t it?  But—­”

“Oh!” That startled cry seemed wrung from her involuntarily.  Then, swiftly, as if her mind had detached itself to look on her own actions that night through his eyes:  “You thought, you believed that I—­” She checked herself, but her look completed the thought.

“I did not know what to think, but I did not think—­that,” he gloomily rejoined.  “Afterwards, the next night, I found out something which made me think—­” He paused.

“Yes, yes, tell me what you thought,” she said nervously.

“I thought it was Thalassa.”

She shook her head.

“Who was it then?  The latest theory of the police is that I had something to do with it.  They’re looking for both of us.  They must have found out that I was at Flint House that night.  It’s too late to tell them the truth now, not that they were likely to have believed me at any time.  Why, my own father believes that I did this thing.”  He laughed discordantly.  “I tried to convince your father’s lawyer of your innocence, and I might have told him the truth if he had been sympathetic.  I don’t know, though,” he added anxiously.  “I had to consider your position all along.  If my story was disbelieved it only made it worse for you.  If it was not Thalassa, who could it have been?  Have you any idea—­the faintest suspicion?”

Again she shook her head.  She made an effort to look at him, but there were tears in her eyes for the first time.  His hand was resting on the table, and she touched it gently with her fingers.