“I know, doctor.” French spoke soothingly. “But none of us are infallible, and if you made a mistake it’s only what every one does at one time or another. Your reasons for giving the certificate were very convincing, and if they were not sound in this case it is only because this case is one in a million. Don’t worry about the certificate. Instead, just sit down and recall the appearance of the body and see if you can think of another cause of death. If you’re not able to give a definite opinion we can still get something by elimination. I take it, for example, the man’s skull was not battered in nor his throat cut? That limits the affair. You see what I mean?” “Oh, I see right enough, and naturally I’ll give you all the help I can. But tell me first, have you found the body?” “No, nor have I the faintest idea where to look. That will be my next job, I suppose. I don’t even say it’s murder. But it may be, and if you can answer my question it might be a considerable help.” Dr. Emerson thought for some moments. “Well,” he said at last, “I must admit that murder is _possible_, though I don’t for a moment believe death occurred otherwise than as I said. As to possible methods, there were no obvious wounds on the body and violence in the literal sense is therefore unlikely. A sharp blow over the heart or on the stomach might have caused heart failure without leaving physical marks, but in such a case the features would have looked distressed. For the same reason death from the shock of a sudden fright or start may be ruled out. It is of course true that certain kinds of poison might have been administered. A whiff of hydrocyanic acid gas would cause almost instantaneous death and produce the same appearance as death from natural causes. An injection of cocaine would do the same where there was heart disease, and there are other similar agents. But in these cases the difficulty of the average man in obtaining the substances in question and also in knowing how to use them if obtained, is so great that I think they might all be ruled out. No, Inspector, amazing as your discovery seems, I cannot think you are right in assuming murder.” “But,” thought French, though he did not put his thought into words, “if the man you suspect spent the best years of his life as male nurse in a medical institution, these difficulties pretty well vanish.” But he concealed his satisfaction, and, instead, simulated disappointment. “That seems very reasonable, doctor, I must admit. At the same time I shall have to put inquiries in hand as to whether any one recently tried to obtain cocaine or those other things you have mentioned. Of course, I don’t say that necessarily I am right in my ideas.” “I don’t think you are right, though I confess I’m absolutely lost in amazement about that coffin. Come now, Inspector, you must know more than you pretend. Are your ideas hopelessly confidential?”