m.' The hour is not quite accurate, but near enough, since the context shows that a 'friend' had just called and given certain information which had determined the writer to leave London 'to-morrow'-- meaning today--'or Wednesday at latest.' So you see, Mr.Theydon, if the unknown is an honest man, he will soon hear of the hue and cry raised by the murder, and declare himself to the police.
Indeed, for all I know, he may have reported himself to the Yard already.

In that event you will probably meet him again quite soon." An electric bell jarred at the end of the main passage.

It smote on their ears with the loud emphasis of a pistol shot.

Even the detectives were startled, and Winter said, in a tone of distinct annoyance: "Go and see who the deuce that is, Furneaux." Furneaux returned promptly with Bates, pallid and apologetic.
"Beg pardon, sir," said the intruder, addressing Theydon, but allowing his eyes to roam furtively about the room as though he expected to see something ghoul-like and sinister, "Mr.Forbes has rung up--" Theydon's voice literally quavered.

For the first time in his life he knew why a woman shrieks in the stress of sudden excitement.
"Tell Mr.Forbes I am still engaged with the gentlemen from Scotland Yard," he gasped.