'Yes, I remember wondering once myself what Shakespeare was getting at,' said Tommy. 'I forget whose production it was and who was playing Macbeth, but there was a strong suggestion in that particular production, and Macbeth certainly played it in a way to suggest that he was hinting to the medical attendant that Lady Macbeth would be better out of the way. Presumably the medical attendant took the hint. It was then that Macbeth, feeling safe after his wife's death, feeling that she could no longer damage him by her indiscretions or her rapidly failing mind, expresses his genuine affection and grief for her. "She should have died hereafter."'

'Exactly,' said Dr. Murray. 'It is what I felt about Mrs. Moody. I felt that she should have died hereafter. Not just three weeks ago of no apparent cause.'

Tommy did not reply. He merely looked at the doctor inquiringly.

'Medical men have certain problems. If you are puzzled over the cause of a patient's death there is only one sure way to tell. By a post mortem. Post mortems are not appreciated by relatives of the deceased, but if a doctor demands a post mortem and the result is, as it perfectly well may be, a case of natural causes, or some disease or malady which does not always give outward signs or symptoms, then the doctor's career can be quite seriously affected by his having made a questionable diagnosis.'

'I can see that it must have been difficult.'

'The relatives in question are distant cousins. So I took it upon myself to get their consent as it was a matter of medical correctness, to know the cause of death. When a patient dies in her sleep it is advisable to add to one's medical knowledge. I wrapped it up a good bit, mind you, didn't make it too formal. Luckily they couldn't care less. I felt very relieved in mind.'

'Once the autopsy had been performed and if all was well, I could give a death certificate without a qualm. Anyone can die of what is amateurishly called heart failure, from one of several different causes. Actually Mrs. Moody's heart was in really very good shape for her age. She suffered from arthritis and rheumatism and occasional trouble with her liver, but none of these things seemed to accord with her passing away in her sleep.'

Doctor Murray came to a stop. Tommy opened his lips and then shut them again. The doctor nodded.

'Yes, Mr. Beresford. You can see where I am tending. Death has resulted from an overdose of morphine.'

'Good Lord!' Tommy stared and the ejaculation escaped him.

'Yes. It seemed quite incredible, but there was no getting away from the analysis. The question was: How was that morphine administered? She was not on morphine. She was not a patient who suffered pain. There were three possibilities, of course. She might have taken it by accident. Unlikely. She might have got hold of some other patient's medicine by mistake but that again is not particularly likely. Patients are not entrusted with supplies of morphine, and we do not accept drug addicts who might have a supply of such things in their possession. It could have been deliberate suicide but I should be very slow to accept that. Mrs. Moody, though a worrier, was of a perfectly cheerful disposition and I am quite sure had never thought of ending her life. The third possibility is that a fatal overdose was deliberately administered to her. But by whom, and why? Naturally, there are supplies of morphine and other drugs which Miss Packard as a registered hospital nurse and matron, is perfectly entitled to have in her possession and which she keeps in a locked cupboard. In such cases as sciatica or rheumatoid arthritis there can be such severe and desperate pain that morphine is occasionally administered. We have hoped that we may come across some circumstance in which Mrs. Moody had a dangerous amount of morphine administered to her by mistake or which she herself took under the delusion that it was a cure for indigestion or insomnia. We have not been able to find any such circumstances possible. The next thing we have done, at Miss Packard's suggestion and I agreed with her, is to look carefully into the records of such deaths as have taken place at Sunny Ridge in the last two years. There have not been many of them, I am glad to say. I think seven in all, which is a pretty fair average for people of that age group. Two deaths of bronchitis, perfectly straightforward, two of flu, always a possible killer during the winter months owing to the slight resistance offered by frail, elderly women. And three others.'

He paused and said, 'Mr. Beresford, I am not satisfied about those three others, certainly not about two of them. They were perfectly probable, they were not unexpected, but I will go as far as saying that they were unlikely. They are not cases that on reflection and research I am entirely satisfied about. One has to accept the impossibility that, unlikely as it seems, there is someone at Sunny Ridge who is, possibly for mental reasons, a killer. An entirely unsuspected killer.'

There was silence for some moments. Tommy gave a sigh. 'I don't doubt what you've told me,' he said, 'but all the same, frankly, it seems unbelievable. These things-surely, they can't happen.'

'Oh yes,' said Dr. Murray grimly, 'they happen all right. You go over some of the pathological cases. A woman who took on domestic service. She worked as a cook in various households. She was a nice, kind, pleasant-seeming woman, gave her employers faithful service, cooked well, enjoyed being with them. Yet, sooner or later, things happened. Usually a plate of sandwiches. Sometimes picnic food. For no apparent motive arsenic was added. Two or three poisoned sandwiches among the rest. Apparently sheer chance dictated who took and ate them. There seemed no personal venom. Sometimes no tragedy happened. The same woman was three or four months in a situation and there was no trace of illness. Nothing. Then she left to go to another job, and in that next job, within three weeks, two of the family died after eating bacon for breakfast. The fact that these things happened in different parts of England and at irregular intervals made it some time before the police got on her track. She used a different name, of course, each time. But there are so many pleasant, capable middle-aged women who cook, it was hard to find out which particular woman it was.'

'Why did she do it?'

'I don't think anybody has ever really known. There have been several different theories, especially of course by psychologists. She was a somewhat religious woman and it seems possible that some form of religious insanity made her feel that she had a divine command to rid the world of certain people, but it does not seem that she herself had borne them any personal animus.'

'Then there was the French woman, Jeanne Gebron, who was called The Angel of Mercy. She was so upset when her neighbours had ill children, she hurried to nurse those children. Sat devotedly at their bedside. There again it was some time before people discovered that the children she nursed never recovered. Instead they all died. And why? It is true that when she was young her own child died. She appeared to be prostrated with grief. Perhaps that was the cause of her career of crime. If her child died so should the children of other women. Or it may be, as some thought, that her own child was also one of the victims.'

'You're giving me chills down my spine,' said Tommy.

'I'm taking the most melodramatic examples,' said the doctor. 'It may be something much simpler than that. You remember in the case of Armstrong, anyone who had in any way offended him or insulted him, or indeed, if he even thought anyone had insulted him, that person was quickly asked to tea and given arsenic sandwiches. A sort of intensified touchiness. His first crimes were obviously mere crimes for personal advantage. Inheriting of money. The removal of a wife so that he could marry another woman.'

'Then there was Nurse Warriner who kept a Home for elderly people. They made over what means they had to her, and were guaranteed a comfortable old age until death came. But death did not delay very long. There, too, it was morphine that was administered-a very kindly woman, but with no scruples-she regarded herself, I believe, as a benefactor.'

'You've no idea, if your surmise about these deaths is true, who it could be?'

'No. There seems no pointer of any kind. Taking the view that the killer is probably insane, insanity is a very difficult thing to recognize in some of its manifestations. Is it somebody, shall we say, who dislikes elderly people, who had been injured or has had her life ruined or so she thinks, by somebody elderly? Or is it possibly someone who has her own ideas of mercy killing and thinks that everyone over sixty years of age should be kindly exterminated. It could be anyone, of course. A patient? Or a member of the staff-a nurse or a domestic worker?'

'I have discussed this at great length with Millicent Packard who runs the place. She is a highly competent woman, shrewd, businesslike, with keen supervision both of the guests there and of her own staff. She insists that she has no suspicion and no clue whatever and I am sure that is perfectly true.'

'But why come to me? What can I do?'

'Your aunt, Miss Fanshawe, was a resident there for some years-she was a woman of very considerable mental capacity, though she often pretended otherwise. She had unconventional ways of amusing herself by putting on an appearance of senility. But she was actually very much all there. What I want you to try and do, Mr. Beresford, is to think hard-you and your wife, too. Is there anything you can remember that Miss Fanshawe ever said or hinted, that might give us a clue? Something she had seen or noticed, something that someone had told her, something that she herself had thought peculiar. Old ladies see and notice a lot, and a really shrewd one like Miss Fanshawe would know a surprising amount of what went on in a place like Sunny Ridge. These old ladles are not busy, you see, they have all the time in the world to look around them and make deductions-and even jump to conclusions-that may seem fantastic, but are sometimes, surprisingly, entirely correct.'

Tommy shook his head. 'I know what you mean, but I can't remember anything of that kind.'

'Your wife's away from home, I gather. You don't think she might remember something that hadn't struck you?'

'I'll ask her-but I doubt it.' He hesitated, then made up his mind. 'Look here, there was something that worried my wife about one of the old ladies, a Mrs. Lancaster.'

'Mrs. Lancaster? Yes?'

'My wife's got it into her head that Mrs. Lancaster has been taken away by some so-called relations very suddenly. As a matter of fact, Mrs. Lancaster gave a picture to my aunt as a present, and my wife felt that she ought to offer to return the picture to Mrs. Lancaster, so she tried to get in touch with her to know if Mrs. Lancaster would like the picture returned to her.'