Lanagan was taking the lead, but I was not altogether surprised when we finally found ourselves in the neighbourhood of the Northrup home. Nor was I altogether surprised when Chief Leslie, that shrewd and veteran thief-taker, suddenly stepped from a doorway. My mind shot ahead to the Northrup home, a few doors away, and I could not bring myself to believe it could be possible that she was a principal. “Brady is above,” said Leslie. “He says she came in about twenty minutes ago. We had better move on her.” “Immediately,” said Lanagan, and in a moment more we were all three before the door to a lower flat of the old-fashioned sort, with a bell jangling noisily as Lanagan pulled out the handle. It was Miss Northrup who answered the ring. She had on a dressing gown, and her hair, I could see, had been taken down for retiring and then gathered in a loose coil on her head, probably when the bell rang. She opened the door but a few inches. “We would like to speak with you a moment, Miss Northrup,” said Lanagan. He indicated the chief. “This is Chief Leslie.” “Kindly permit us to enter,” said the chief. There was a shadow of authority in his tone, and I knew that Lanagan and the chief were planning a drive on the girl and that something would be stirring in this old-fashioned flat before long. She hesitated a moment and then threw the door wide open and motioned us into the parlour. In the hall a gas jet burned dimly, as though for some member of the family who was not yet home. She reached up and turned on the parlour light, and as she did so her loosely coiled hair tumbled about her shoulders. As the light struck down upon her features they had an appearance almost tragic. “Be seated,” she said; it needed no expert eye to detect in her drawn lips the evidence of nervous tension. “Madam,” said Leslie abruptly, snapping his jaws like a trap--and I knew this twenty-year-old girl was in for the third degree--“unless you at this time make a clean breast of all that you know concerning the murder of your employer, Ralph Monteagle, it will be necessary for me to book you for murder as an accessory before the fact.” She started violently; her bosom began to rise and fall quickly; it was evident a breakdown was imminent, but she managed to say with considerable smoothness: “I know nothing more than I have already told the police and the reporters.” Lanagan, fierce eagerness glittering in his eyes, stepped before her.