I could not find the Egyptian, and thus it was probable I had killed him as had been said.

What must I do?
This, and this only.

I must go to Scotland Yard, and relate to the authorities my whole story.

I must tell them of Voltaire's influence over me, and that it was probable I had, while held under a mesmerist's spell, killed the man I had been trying to find.
This was all.

It _might_ bring this villain under suspicion, and, if so, it would hinder him from exacting the fulfilment of Gertrude Forrest's promise.
It was at best but an uncertain venture, but it was all I could do.