"No doubt. But there's a difference between expectation and certainty. There's also another factor which you're leaving out of account. When Clement Kane was shot, James Kane, standing in the garden hall, saw nothing. Not so much as an agitation in the bushes. You may contend, if you like, that it would have been possible for the murderer to have shot Clement through the study window and to have dashed into the cover of the shrubbery in a very few seconds. But I've seen that garden hall. James Kane states that the door into the garden was open; if it had been shut he could still have seen out, because the upper panels are glazed. The sound of a shot so near at hand must have had the effect of making him look round immediately. An involuntary reaction. He says he did look round and stepped out at once through the open door. I've stood in that garden hall, Hemingway, and I've seen that it commands a view of the shrubbery. I can't understand how James Kane could have failed to observe any movement at all in the garden. If the murderer escaped, not into the shrubbery but by the path running along the side of the house to the front avenue, it is incredible that Kane should not have caught a glimpse of him when he looked out. He heard no footsteps on the gravel, either before or after the shot. One can argue that, as he had only just entered the garden hall when the shot was fired, he need not necessarily have heard anyone approaching the study. But surely he must have heard a hasty retreat? If we are to exonerate James Kane himself, we look like being faced with a far more fantastic possibility, which is that old Mrs. Kane murdered Clement, and James Kane knows it."
"Revenge?" inquired the sergeant.
"That, and dislike of having him and his wife firmly established at Cliff House. She believes that Clement killed her son: that much seems to be certain. One of the doubts in my mind is whether she could have handled as heavy a gun as a .38."
"Yes, but if she did it, and Jim Kane knows it, what about the attempts on him?" objected the sergeant. "Are you making Sir Adrian responsible for them?"
"It's a possibility. They may, on the other hand, have been faked by himself, partly to throw me off Mrs. Kane's scent, partly to protect himself. Tortuous, I know, but the human brain is tortuous."
The sergeant sighed. "You're making it sound worse than ever, Chief. I'm blowed if I see where we are now."
"On the wrong track," replied Hannasyde promptly. "We've got to find the gun which shot Clement Kane."
"What you might call a tall order," remarked the sergeant. "If it was James Kane who did it, the odds are he took it out to sea in that boat of his and dropped it overboard. If it was Dermott, after all, we might find it at the bottom of the lake, but more likely he disposed of it miles from here. If it was young Mansell, there's no saying where he got rid of it. Of course, I had a look in the shrubbery, but there was no sign of the ground having been disturbed, and I can't say I expected any. It isn't in human nature to leave the weapon close to the scene of the crime, now, is it?"
"That's a ready-made argument which won't stand investigation," answered Hannasyde. "I agree that in nine cases out of ten you won't find the weapon near the scene of the crime, except of course in those instances where the murder has been faked to look like suicide. But the more I go into this case the more I feel convinced that we're up against a very astute mind. Moreover, unless the murderer was either Paul Mansell or Trevor Dermott, we have to remember that he had very little time in which to dispose of the gun before confronting Inspector Carlton. It's true Carlton didn't search anyone, but I hardly think the murderer would have been foolhardy enough to have run the risk of being found with the weapon on his person. Instinct would urge him to get rid of it immediately."
"Yes, that's good psychology, Super," conceded the sergeant. "What are we going to do? Drag the lake?"
"If all else fails. But neither James Kane nor Mrs. Kane could have disposed of the revolver as far from the house as that, let alone the certainty of their being seen by Dermott and Mrs. Clement Kane, who were there. I think it must be concealed in, or near, the house."
"That bank of rhododendrons? Terrible Timothy searched there, and so I did myself."
"No, I thought of that; but I don't believe we shall find it there. If the murderer hid it there he must surely have buried it, for we were bound to search that bank. I don't see him doing that. It would have taken time, he might have been seen from the house, and at any moment one of the gardeners might have passed by. If he got rid of the gun on the premises he must have done it quickly. Now, isn't there a big rain tub standing not ten feet from the study window?"
The sergeant blinked at him. "There is, of course, but are you suggesting that anyone would have the almighty brass to drop the gun in there where it might be discovered any minute, Super? Why, he'd have to be crazy! The very fact of the tub being so handy would be enough to put him off!"
"Perhaps he banked on us thinking that," said Hannasyde with a slight smile.
The sergeant scratched his chin. "I'm bound to say it's about the last place I'd look for the gun. As a matter of fact, I've never banked much on finding it there at all."
"Nor I. Which is where I think we may have been wrong. We'll go and investigate that tub."
But when the sergeant was confronted with the big green rain tub standing so blatantly against the wall of the house, he shook his head and said: "He wouldn't have had the nerve."
"Whoever committed this crime had plenty of nerve," replied Hannasyde grimly. "See if you can find a long stick."
The sergeant said: "That's easy," and moved towards a round bed of roses beyond the edge of the shrubbery and calmly uprooted the stake that supported one of the standard trees. Hannasyde took it from him, and, mounting the brick platform on which the tub stood, lifted the wooden lid, and lowered the stick into the dark water, probing and stirring. The sergeant watched him with interest but without hope.
"There is something lying on the bottom!" Hannasyde said. "I've just moved it." He withdrew the stake, threw it aside, and stepped down from the ledge of bricks. "Turn that spigot, Sergeant! I want the tub emptied."
"That'll make us popular with the head gardener," murmured the sergeant, but he turned the spigot and stood back while the water splashed down onto the gravel path, forming first a pond and then a river.
It was not the head gardener who took exception to the gathering flood, but Ogle, bouncing out upon the two detectives from the garden hall. "You turn that tap off this instant!" she commanded angrily. "The idea of it, making all this mess! You've got no right to come here ruining the flower-beds and making the place not fit to go near! What do you want with that tub? Who gave you leave to touch it, I should like to know?"
Hannasyde paid no attention, leaving the task of getting rid of her to his subordinate, who accomplished it in record time. She darted back into the house, promising to tell Mr. James what damage was being done to his property, and in a few moments came back with him at her heels. "There, sir!" she said. "Tell them to stop it this instant! The mistress wouldn't allow it, not for one moment! The impudence of it!"
"All right, Ogle! You trot along," said Jim. He looked from the lake at his feet to the superintendent and said, as Ogle withdrew reluctantly into the house: "I say, must you? You're not exactly improving this bit of garden. What's the great idea?"
"I shouldn't do it if I didn't think it necessary, Mr. Kane," said Hannasyde rather curtly. "It won't do any serious damage to the garden, I assure you. The tub's only half-full."
"Thanks very much," said Jim, his jaw hardening a little. "And now perhaps you'll explain just what you're up to?"
"Certainly," said Hannasyde, looking at him under his brows. "I am pursuing an investigation. Have you any objection?"