“I understand,” said Kilsip, nodding his head.  “Woman?”

“No, nothing of the kind,” retorted Calton, hastily.  “I thought so at first, but I was wrong.  He went to see a dying woman, who wished to tell him something.”

“What about?”

“That’s just what I can’t tell you,” answered Calton quickly.  “It must have been something important, for she sent for him in great haste—­and he was by her bedside between the hours of one and two on Friday morning.”

“Then he did not return to the cab?”

“No, he did not, he went to keep his appointment, but, for some reason or other, he won’t tell where this appointment was.  I went to his rooms to-day and found this half-burnt letter, asking him to come.”

Calton handed the letter to Kilsip, who placed it on the table and examined it carefully.

“This was written on Thursday,” said the detective.

“Of course—­you can see that from the date; and Whyte was murdered on Friday, the 27th.”

“It was written at something Villa, Toorak,” pursued Kilsip, still examining the paper.  “Oh!  I understand; he went down there.”

“Hardly,” retorted Calton, in a sarcastic tone.  “He couldn’t very well go down there, have an interview, and be back in East Melbourne in one hour—­the cabman Royston can prove that he was at Russell Street at one o’clock, and his landlady that he entered his lodging in East Melbourne at two—­no, he wasn’t at Toorak.”

“When was this letter delivered?”

“Shortly before twelve o’clock, at the Melbourne Club, by a girl, who, from what the waiter saw of her, appears to be a disreputable individual—­you will see it says bearer will wait him at Bourke Street, and as another street is mentioned, and as Fitzgerald, after leaving Whyte, went down Russell Street to keep his appointment, the most logical conclusion is that the bearer of the letter waited for him at the corner of Bourke and Russell Streets.  Now,” went on the lawyer, “I want to find out who the girl that brought the letter is!”

“But how?”

“God bless my soul, Kilsip!  How stupid you are,” cried Calton, his irritation getting the better of him.  “Can’t you understand—­that paper came from one of the back slums—­therefore it must have been stolen.”

A sudden light flashed into Kilsip’s eyes.

“Talbot Villa, Toorak,” he cried quickly, snatching up the letter again, and examining it with great attention, “where that burglary took place.”

“Exactly,” said Calton, smiling complacently.  “Now do you understand what I want—­you must take me to the crib in the back slums where the articles stolen from the house in Toorak were hidden.  This paper”—­pointing to the letter—­“is part of the swag left behind, and must have been used by someone there.  Brian Fitzgerald obeyed the directions given in the letter, and he was there, at the time of the murder.”

“I understand,” said Kilsip, with a gratified purr.  “There were four men engaged in that burglary, and they hid the swag at Mother Guttersnipe’s crib, in a lane off Little Bourke Street—­but hang it, a swell like Mr. Fitzgerald, in evening dress, couldn’t very well have gone down there unless—­”