"Eltham, in Kent. Morton Grange, Eltham," said Mr. Marchmont. "And now, if you have all the information that you require, I must really be off, and so must Mr. Curtis."
The two men shook our hands and hurried away, leaving Thorndyke gazing meditatively at the dingy flower-beds.
"A strange and interesting case, this, Jervis," said he, stooping to peer under a laurel-bush. "The inspector is on a hot scent—a most palpable red herring on a most obvious string; but that is his business. Ah, here comes the porter, intent, no doubt, on pumping us, whereas—" He smiled genially at the approaching custodian, and asked: "Where did you say those houses fronted?"
"Cotman Street, sir," answered the porter. "They are nearly all offices."
"And the numbers? That open second-floor window, for instance?"
"That is number six; but the house opposite Mr. Hartridge's rooms is number eight."
"Thank you."
Thorndyke was moving away, but suddenly turned again to the porter.
"By the way," said he, "I dropped something out of the window just now—a small flat piece of metal, like this." He made on the back of his visiting card a neat sketch of a circular disc, with a hexagonal hole through it, and handed the card to the porter. "I can't say where it fell," he continued; "these flat things scale about so; but you might ask the gardener to look for it. I will give him a sovereign if he brings it to my chambers, for, although it is of no value to anyone else, it is of considerable value to me."
The porter touched his hat briskly, and as we turned out at the gate, I looked back and saw him already wading among the shrubs.