Now that the blush had faded from her cheek, I realised that she was indeed looking wretchedly pale and thin, and as she leaned eagerly forward I was shocked to see how her lips twitched and her hands trembled. "So it was you who first put the police on the Frenchman's tracks?" she demanded. "Yes. But you must remember that the success my first attempt at detective work has met with is largely due to the exceptional opportunities I have had for investigating this case. You may have noticed that no hat was found with the corpse and the police have therefore been searching everywhere for one that could reasonably be supposed to have belonged to the murdered man. Now, I may tell you, although I must ask you not to mention it, as the police do not yet wish that the fact become known, that it was I who found this missing hat in Argot's possession. But I can't boast much of my discovery, because the man brought it into my office himself. All I really did was to keep my eyes open, you see." I tried to speak modestly, for I was conscious of a secret pride in my achievement. "I really cannot see why you should have taken upon yourself to play the detective!" I was so startled by May's sudden attack on me that for a moment I remained speechless. Luckily, Mrs. Derwent saved me from the necessity of replying, by rising from her chair. Slipping her arm through Miss Cowper's, she said--casting a significant glance at me: "We will leave these people to quarrel over the pros and cons of amateur work, and you and I will go and see what Mr. Norman is doing over there in that arbour all by himself." Fred had mentioned that at times May seemed alarmingly oblivious to what was going on around her, and I now noticed with profound anxiety that she appeared entirely unconscious of the departure of her mother and friend. "Just suppose for a moment that this man Argot," she went on, as if our conversation had not been interrupted, "is innocent, and yet owing to an unfortunate combination of circumstances, is unable to prove himself so. Who should be held responsible for his death but you, Dr. Fortescue! Had you not meddled with what did not concern you, no one would have thought of suspecting this wretched Frenchman! You acknowledge that yourself?"