"Forgive me if I say that I am insensible to the sanity of your cavalier methods." His tone betrayed only contempt. "May I hope that for the present your inquisition is ended?"
"I think that will be all, doctor," returned Markham politely. "May I have a taxicab called for you?"
"Your consideration overwhelms me. But my car is below." And Doctor Lindquist haughtily withdrew.
Markham immediately summoned Swacker and sent him for Tracy. The detective came at once, polishing his pince-nez and bowing affably. One would have taken him for an actor rather than a detective, but his ability in matters requiring delicate handling was a byword in the department.
"I want you to fetch Mr. Louis Mannix again," Markham told him. "Bring him here at once; I'm waiting to see him."
Tracy bowed genially and, adjusting his glasses, departed on his errand.
"And now," said Markham, fixing Vance with a reproachful look, "I want to know what your idea was in putting Lindquist on his guard about the night nurse. Your brain isn't at par this afternoon. Do you think I didn't have the nurse in mind? And now you've warned him. He'll have until eleven to-morrow morning to coach her in her answers. Really, Vance, I can't conceive of anything better calculated to defeat us in our attempt to substantiate the man's alibi."
"I did put a little fright into him, didn't I?" Vance grinned complacently. "Whenever your an-
