Dr. Fell paused, wheezing heavily.
"But Margot Marsh, don't you see, still had the will to live? Now we can say 'did' instead of 'perhaps' or ‘might" have.' An hour later she struggled to semiconsciousness: morphine poisoned, dying, but calling for help. Thorley Marsh heard her. He stumbled into the sitting room—
"And, by thunder, but this man got a jolt! The moaning woman may be in a hysterical attack, yes. Of course! No doubt! But that brown bottle labelled 'poison.' My God, can she have meant what she said about suicide? Thorley Marsh rushed back to the medicine chest. The bottle had gone."
Dr. Fell drew a deep breath, puffing out the ribbon on his eyeglasses.
"That," he said, "was what I had to establish when I first questioned our friend Marsh. It had seemed clear from the first, by his incessant harping to everybody on the subject of a certificate of death from natural causes, that he at least suspected the possibility of suicide. So to avoid scandal, he lied.”
"But, if I could trip him up and get him to verify what I believed to be the truth, then I should be on safe and certain ground. And I did so. Will you concede that what I once told you was no paradox? It was because Marsh had been telling lies that I then knew he was telling the truth."
"And yet," Holden demanded, "Thorley didn't even tell Dr. Shepton he suspected Margot might have poisoned herself?"
"No. Because Dr. Shepton (if you recall) instantly told him it was a hysterical attack and probably not even very serious. Afterward it was too late. So he lied."
"I can't make Thorley out!" Holden said desperately. "I still don't know whether I ought to apologize to him or wring his neck!"
"And yet," said Dr. Fell, "he is the easiest person of all to understand. Thorley Marsh is a genuinely good-natured person, who likes his friends and will go to any amount of trouble for them, provided only his own self-interest is not seriously threatened." He paused. "There, but for the grace of God . . ."
There was a silence.
"Yes," said Holden. "There, but for the grace of God, go we all."
"And yet," Celia spoke softly, "I hate him. I hate him even when I know Margot was . . . was like that, and he never mistreated her. Maybe it's a dreadful thing to say,
"Oh, ah?" rumbled Dr. Fell. "How is he?" - "They don't know yet. Doris is at the nursing home now. We're expecting her." Celia hesitated. "But I hate him," she said, "for telling you I was crazy and Margot died a natural death and there wasn't any poison bottle, when all the time he knew better! Don, dear! I know what I did was very silly. But do you blame me?" /4No! Of course I don't!"
"Nor I," said Dr. Fell "But, by thunder, young lady, you gave me some very apprehensive moments!"
And Dr. Fell shook his head, massively.
"I informed yon in the Long Gallery," he told Holden, "that this girl was in her right senses. Apparently she'd been seeing ghosts; but, when she saw you and knew you were no ghost, it was obvious she hadn't been suffering from delusions. At the same time, I had to make sure she wasn't..."
"Wasn't what?"
"Manufacturing evidence!" said Dr. Fell.
An expression of awe went over his face.
"When we went out to unseal that tomb," he continued, "I was frightened. Damme, yes! Not because I expected a snpematural occurrence, as you evidently thought But, if this girl had been attempting to manufacture evidence, as seemed likely from that letter, then the police would be after her straightaway.
"At first glance, when we unsealed the vault, there seemed to be nothing wrong except the disarrangement of the coffins. And I was so relieved, so infinitely relieved, that Inspector Crawford noticed it
"I had already, in case it became necessary, tried to put Crawford off the track with much hocus-pocus about the impossibility of entering that vault Then, just when I was feeling better, Crawford's light picked up that infernal bottle where only Celia could have put it. Back I sank into the abyss."
"Dr. Fell," asked Holden, "how in blazes were those coffins moved?"
"Ah, yes." Dr. Fell looked guilty. "I (harrumph) fear my hocus-pocus talk must have deceived you as much as it deceived Crawford."
"Hocus-pocus talk nothing! Yesterday Locke cited a fact even more staggering. The two modern coffins, Margot’8 and that of a bloke named John Devereux, were airtight masses weighing eight hundred pounds each. Who could fling them about?"
"That, you see," explained Dr. Fell, "was the hocus-pocus.
Flung was the word I suggested. But they were not flung.
They were lifted." "All right, then! How were they lifted?"
"Again," said Dr. Fell, "the key clue is Water.'"
"Water?"
"The modern coffins were airtight Therefore they were watertight. They would float" Holden stared at him.
"The country around Caswall, as you've doubtless noticed," said Dr. Fell, is watered by underground springs. The sort of thing the Germans call—"
"Grundwasser!" muttered Holden, with a sudden realization springing into his mind. "Grundwasser!"
"Yes. It rises nearly to the surface of the ground in the autumn and the spring, and sinks back quite quickly in the summer and the winter. Anyone who studied the countryside could make a small bet that during autumn and spring that vault would be flooded.
"It was four feet below ground level, as you saw. As you also breathed, it was distinctly damp. Crawford, when he walked there, left sharp finely printed footprints in the sand, which doesn't happen in completely dry sand; it was damp.
"The new watertight coffins, lifted up four feet and set drifting, were certain to move all over the place. If s not at all surprising that one of them, its head wedged against the back wall, should remain half propped up when the water subsided.
"But the oldest coffin, being sixteenth century and rotted, never moved at all; the water got into it. An eighteenth century coffin was only slewed round, partly moved and no more. You—er—you follow me?"
"Yes," said Holden in a dazed voice.
"Such an occurrence," grunted Dr. Fell, "had never happened before at Caswall. The vault was new. Aside from the old tomb, which was up in a hill and not likely to be troubled by groundwater, it was the only vault in the churchyard. But the phenomenon has been seen often enough in other places." *
"Then the sand on the floor.. ?"
"Naturally there was no footprint. Except for disturbances round the coffins, the effect of slowly rising and falling water on sand would be to make it smoother than before.
"Dash it all! I gave you a hint! The new lock, being far above the reach of the water, turned with a sharp clean click. But the lower hinge of the door, being well within slopping -distance of rising water, squeaked and squealed. It was rusty. Water, water, water!"
*‘See Oddities, by Lieutenant Commander Rupert T. Gould, R. N. (London, Philip Allan & Co. Ltd., 1928, pp. 33-78.)
"And that’s all there was to it?"
"That," agreed Dr. Fell, "was all there was to it"
"I'm the culprit, Don," Celia said in a stifled voice. "I— I found that in a book. I gambled on it happening. Do you hate me very much?"
"Don't be an idiot, my dear! Hate you?"
"But Dr. Fell must resent it"
"By thunder," said Dr. Fell, "I do resent it!"
"You've got every right to. I'm awfully sorry. I was looking for a fake poison bottle that resembled the real one; and in the cellar at Widestairs, where Ronnie must have hidden it I got the real bottle without knowing it. I put it in there when you and I sealed the vault Yon have every right to resent being victimized—"