“They may not be able to fasten this crime upon you, but there will be complications most distasteful.  One’s liberty is well worth keeping—­and then, too, before the case ends, there will be wide publicity—­”

“’Well?” said I.

“That is why you are going to suffer a lapse of memory in the matter of the hour at which you heard that struggle.  As you think it over, it is going to occur to you that it may have been six-thirty, not seven.  Otherwise—­”

“Go on.”

“Otherwise the letter of introduction you gave to the captain will be sent anonymously to Inspector Bray.”

“You have that letter!” I cried.

“Not I,” she answered.  “But it will be sent to Bray.  It will be pointed out to him that you were posing under false colors.  You could not escape!”

I was most uncomfortable.  The net of suspicion seemed closing in about me.  But I was resentful, too, of the confidence in this woman’s voice.

“None the less,” said I, “I refuse to change my testimony.  The truth is the truth—­”

The woman had moved to the door.  She turned.

“To-morrow,” she replied, “it is not unlikely you will see Inspector Bray.  As I said, I came here to give you advice.  You had better take it.  What does it matter—­a half-hour this way or that?  And the difference is prison for you.  Good night.”

She was gone.  I followed into the hall.  Below, in the street, I heard the rattle of her taxi.

I went back into my room and sat down.  I was upset, and no mistake.  Outside my windows the continuous symphony of the city played on —­the busses, the trains, the never-silent voices.  I gazed out.  What a tremendous acreage of dank brick houses and dank British souls!  I felt horribly alone.  I may add that I felt a bit frightened, as though that great city were slowly closing in on me.

Who was this woman of mystery?  What place had she held in the life —­and perhaps in the death—­of Captain Fraser-Freer?  Why should she come boldly to my rooms to make her impossible demand?

I resolved that, even at the risk of my own comfort, I would stick to the truth.  And to that resolve I would have clung had I not shortly received another visit—­this one far more inexplicable, far more surprising, than the first.

It was about nine o’clock when Walters tapped at my door and told me two gentlemen wished to see me.  A moment later into my study walked Lieutenant Norman Fraser-Freer and a fine old gentleman with a face that suggested some faded portrait hanging on an aristocrat’s wall.  I had never seen him before.

“I hope it is quite convenient for you to see us,” said young Fraser-Freer.

I assured him that it was.  The boy’s face was drawn and haggard; there was terrible suffering in his eyes, yet about him hung, like a halo, the glory of a great resolution.

“May I present my father?” he said.  “General Fraser-Freer, retired.  We have come on a matter of supreme importance—­”