I wandered aimlessly, trying to form some resolution. Had any person seen me enter or leave the park on the previous night? If they had then my position was certainly one of peril, for, if arrested on suspicion, I should experience the utmost difficulty in clearing myself. Where was Beryl? I called her Beryl, for that was the name by which I had first known her, and it appeared to me that her cousin had falsely introduced her to me as Feo. Had they both returned to London, or were they still at the Park? At a point beyond Kneller Hall, just then within sight of Twickenham Town, I turned back, and, passing along the boundary of the park to Hounslow railway station, made inquiries of a friendly ticket collector, from whom I learnt that the two ladies had left, with several of the other guests for Waterloo half an hour before. This information decided me. I went on into the town, and, entering the police-station, sought an interview with the inspector. It fortunately happened that Mr Rowling, the sub-divisional inspector from Brentford, a tall, rosy-faced, smart-looking man, was there, and he being the chief of that sub-district of the T Division, I gave him my card and placed myself at his disposal. He had ridden over from Brentford in response to a telegram, and looked a veritable giant in his long police riding-boots and spurs. When I told him that I was a medical man who took a great interest in the detection of crime, and therefore wished to assist in the inquiries regarding the Colonel's death, he looked at me curiously with his merry blue eyes, and again glanced at my card. "Well, Doctor," he said, "I've sent to Scotland Yard as well as to my superintendent at Hammersmith, and we are expecting three or four men from the Criminal Investigation Department to take up the case. They left by the 09:05 from Waterloo, and will arrive here in a few minutes, I hope." "But cannot you give me permission to assist them?" "That, I fear, is beyond my power. The inquiries are, you see, left entirely to them." "But you are chief of this division of police. Surely you can give me permission?" Before replying he made further inquiries as to who I was and where I lived. While we were talking three men in plain clothes entered the office and saluted. Then, after briefly explaining the discovery to them, Rowling introduced me as an assistant. The elder of the three, a thin-faced, dark-haired man, who was an inspector--Bullen by name--while his companions were sergeants, seemed greatly surprised at my application. "It's quite irregular, you know," he said briefly. "But I think, under the circumstances," said Rowling, "that the Doctor might be of some service. He has had previous experience in murder cases, and has just applied to me. Of course I referred him to you, as you are to direct the inquiry." "The difficulty is that any little indiscretion on his part might upset our plans," responded the detective.