charge had twice informed him of the fact, that he roused himself with an
effort and left the building.

Still absorbed in his speculations and anxieties, he walked rapidly away,
and, having narrowly escaped destruction beneath the wheels of more than
one taxi, wandered down Northumberland Avenue on to the Embankment. He
crossed to the farther side, turned mechanically to the right and walked
obliviously on.

It was not until he came nearly to Westminster Bridge that he remembered
the cipher that he had prepared for Gimblet, and that he had, after all,
finally left without giving it to him. It was still in his pocket, and
the discovery roused him from his abstraction.

He took a taxi and drove back to the flats. A motor which had been
standing before the door when he had come out was still there when he
returned; so that, thinking it probably belonged to the lady he had met
on the landing, and guessing that if so the detective was still occupied
with her, he did not ask to see him again, but handed the envelope over
to Higgs when he opened the door, with strict injunctions to take it
immediately to his master.




CHAPTER V


The lady, whose visit to Gimblet dovetailed so neatly with the departure
of his other client on that summer afternoon, was unknown to him.