“Recall all I told you. I thank you sincerely for helping me over a difficulty last night. Shall rejoin you shortly. If questioned say nothing. All depends upon you. Silence!”

I read it through in wonder half a dozen times.

I longed to ring up Ethelwynn Greer again. It would be a weird experience to converse with one whom I had seen dead. Yet I could think of no excuse. Kirk had, no doubt, telegraphed to her, for it seemed that their association was, after all, a very close one.

The day’s work ended, I got into a car and drove to the address in Wimpole Street given me by Leonard Langton.

His chambers were particularly cosy and well-furnished; but his man, a young foreigner, told me that his master had left for Broadstairs by the “Granville” from Victoria that afternoon.

Therefore I remounted in the car, and turned away down into Oxford Street, entirely nonplussed.

I could not discern Kirk’s motive in exposing the tragic circumstances to me. I did not see in what way I could assist him, even though his version of the affair were the true one.

Who was this Kershaw Kirk? That was the main question. Either he was a man of extraordinary power and influence, or else a most cunning and ingenious assassin. Yet was there no suspicion upon Antonio Merli, the foreign servant, who seemed hand-in-glove with Kirk?

Recollection of this caused me to turn the car towards the Euston Road and search along that long, busy thoroughfare for the tobacconist’s shop kept by Antonio’s cadaverous-looking brother, Pietro—the only outsider, apparently, aware of the Professor’s death.

For fully half an hour I searched, until, near the Tottenham Court Road end, I came across a little shop where stationery, newspapers, and tobacco were displayed in the window.