"Should you care to add the case to your annals, my dear Watson," said Holmes that evening, "it can only be as an example of that temporary eclipse to which even the best-balanced mind may be exposed. Such slips are common to all mortals, and the greatest is he who can recognize and repair them. To this modified credit I may, perhaps, make some claim. My night was haunted by the thought that somewhere a clue, a strange sentence, a curious observation, had come under my notice and had been too easily dismissed. Then, suddenly, in the gray of the morning, the words came back to me. It was the remark of the undertaker's wife, as reported by Philip Green. She had said, 'It should be there before now. It took longer, being out of the ordinary.' It was the coffin of which she spoke. It had been out of the ordinary. That could only mean that it had been made to some special measurement. But why? Why? Then in an instant I remembered the deep sides, and the little wasted figure at the bottom. Why so large a coffin for so small a body? To leave room for another body. Both would be buried under the one certificate. It had all been so clear, if only my own sight had not been dimmed. At eight the Lady Frances would be buried. Our one chance was to stop the coffin before it left the house. "It was a desperate chance that we might find her alive, but it WAS a chance, as the result showed. These people had never, to my knowledge, done a murder. They might shrink from actual violence at the last. The could bury her with no sign of how she met her end, and even if she were exhumed there was a chance for them. I hoped that such considerations might prevail with them. You can reconstruct the scene well enough. You saw the horrible den upstairs, where the poor lady had been kept so long. They rushed in and overpowered her with their chloroform, carried her down, poured more into the coffin to insure against her waking, and then screwed down the lid. A clever device, Watson. It is new to me in the annals of crime. If our ex-missionary friends escape the clutches of Lestrade, I shall expect to hear of some brilliant incidents in their future career."