“Then you don’t think he came back.”

“I am certain he did not, for, as Brian told you, there are plenty of young men who wear the same kind of coat and hat as he does.  Who the second man who got into the cab was I do not know, but I will swear that it was not Brian.”

“And you are going to look for that letter?”

“Yes, in Brian’s lodgings.”

“He might have burnt it.”

“He might have done a thousand things, but he did not,” she answered.  “Brian is the most careless man in the world; he would put the letter into his pocket, or throw it into the waste-paper basket, and never think of it again.”

“In this case he did, however.”

“Yes, he thought of the conversation he had with the writer, but not of the letter itself.  Depend upon it, we shall find it in his desk, or in one of the pockets of the clothes he wore that night.”

“Then there’s another thing,” said Calton, thoughtfully.  “The letter might, have been delivered to him between the Elizabeth Street Railway Station and the Club.”

“We can soon find out about that,” answered Madge; “for Mr. Rolleston was with him at the time.”

“So he was,” answered Calton; “and here is Rolleston coming down the street.  We’ll ask him now.”

The cab was just passing the Burke and Wills’ monument, and Calton’s quick eye had caught a glimpse of Rolleston walking down the left-hand side.  What first attracted Calton’s attention was the glittering appearance of Felix.  His well-brushed top hat glittered, his varnished boots glittered, and his rings and scarf-pin glittered; in fact, so resplendent was his appearance that he looked like an animated diamond coming along in the blazing sunshine.

The cab drove up to the kerb, and Rolleston stopped short, as Calton sprang out directly in front of him.  Madge lay back in the cab and pulled down her veil, not wishing to be recognised by Felix, as she knew that if he did it would soon be all over the town.

“Hallo! old chap,” said Rolleston, in considerable astonishment.  “Where did you spring from?”

“From the cab, of course,” answered Calton, with a laugh.

“A kind of Deus ex MACHINA,” replied Rolleston, attempting a bad pun.

“Exactly,” said Calton.  “Look here, Rolleston, do you remember the night of Whyte’s murder—­you met Fitzgerald at the Railway Station.”

“In the train,” corrected Felix.

“Well, well, no matter, you came up with him to the Club.”

“Yes, and left him there.”

“Did you notice if he received any message while he was with you?”

“Any message?” repeated Felix.  “No, he did not; we were talking together the whole time, and he spoke to no one but me.”

“Was he in good spirits?”

“Excellent, made me laugh awfully—­but why all this thusness?”

“Oh, nothing,” answered Calton, getting back into the cab.  “I wanted a little information from you; I’ll explain next time I see you—­ Good-bye!”