"Because he is always poking and prying about," said Kilsip, forgetting, in his indignation, that such poking and prying formed part of detective business. "But, at any rate," he went on quickly, "if Mr. Fitzgerald did leave Mr. Whyte, the only chance he's got of proving his innocence is that he did not come back, as the cabman alleged." "Then, I suppose, you think that Fitzgerald will prove an ALIBI," said Calton. "Well, sir," answered Kilsip, modestly, "of course you know more about the case than I do, but that is the only defence I can see he can make." "Well, he's not going to put in such a defence." "Then he must be guilty," said Kilsip, promptly. "Not necessarily," returned the barrister, drily. "But if he wants to save his neck, he'll have to prove an ALIBI," persisted the other. "That's just where the point is," answered Calton. "He doesn't want to save his neck." Kilsip, looking rather bewildered, took a sip of whisky, and waited to hear what Mr. Calton had to say. "The fact is," said Calton, lighting a fresh cigar, "he has some extraordinary idea in his head. He refuses absolutely to say where he was on that night." "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?"