Professor Smithers made an angry explosive noise, and I saw Inspector Fitzjohn hastily repress a smile.
"Consider Parker," Pons went on, as though there had been no interruption. "Motive, my dear fellow. Always consider motive. There were no strong ones in this case. Bulstrode had already been eliminated as a prospective son-in-law. Why risk getting oneself hanged by dropping a hammer on him? The revenge element in Miss Smithers's case would have been ridiculous. She had achieved her object and had become reengaged to my client. These young people had everything to live for."
"But the mason you interviewed, Pons," I said irritatedly. "He had a grudge, surely."
"Certainly, Parker, but the whole thing was too farfetched. And he made one point of great significance in his talk with us. Two, if one takes into account that Bulstrode was a man who could go absolutely berserk on occasion and do ridiculous things on impulse. You have already heard how he tore down a perfectly good wall in an argument with Dobbs. I made it my business to check that story thoroughly this morning. It was perfectly true and it was corroborated by at least half a dozen of his co-workers."
"What are we left with, then, Mr. Pons?" said Inspector Fitzjohn, somewhat desperately.
"A hammer, Inspector," said Pons, a mischievous twinkle in his eye.
"A Hammer of Hate, as picturesquely described by Professor Smithers. A particularly apt description, though not in the way he intended. The general mistake everyone made, myself included, was that the hammer used in the murder was flung or dropped from the top of the tower. Apart from the impossibility of ensuring accuracy from a hundred feet up and the incredible coincidence of Bulstrode stopping at the exact spot and standing there until Fernchurch had taken perfect aim, the hammer was never on top of the tower."
Fitzjohn's jaw visibly quivered.
"Never there, Mr. Pons? How can you possibly know that?"
"Common sense, Inspector," said Pons calmly. "It was merely assumed, because there were a good many tools on the tower top, that the hammer was among them. But it was a special hammer. Bulstrode's own, in fact, which he habitually carried and with which he tested his men's work. The clue lay in the statement made by Dobbs to myself and Dr. Parker last night, Inspector, and which your own men must have overlooked. Dobbs told us that Bulstrode 'got his hammer, the special one with the crowbar handle'. That made the whole thing perfectly plain in my mind but I could not quite fit the pieces together. The incident of Dobbs and the wall took place weeks ago, but I confirmed from Bulstrode's staff this morning that he always carried the hammer; it was as indispensable to him as a pencil and drawing paper to an architect. When I combined this fact with Miss Smithers's statement, the sequence became more clear. It was not until you directed my attention to the elementary matter of Miss Smithers's windowsill this morning, Parker, that the whole thing came into focus."
"I confess it is not at all clear, Pons."
"My dear fellow, Bulstrode was a vindictive, vengeful man. He considered he had been wronged by Fernchurch and Miss Smithers. It rankled and he was not a man to let such things go lightly. He avoided an open confrontation with my client. But on the morning of his death he was inspecting the work at the base of this tower. You may be sure he had an ulterior motive. That was, I have no doubt, to see Miss Smithers and plead his case again. He had no idea that Fernchurch was on the battlements; he had no reason to know and Mr. Fernchurch himself has told us that at no time did he go near the edge of the tower. I absolutely believe him."
"Thank you, Mr. Pons."
"All very well, Mr. Pons," said Inspector Fitzjohn warily. "But what exactly are you trying to tell us?"
Solar Pons stepped away from the fireplace and his eyes were very bright.
"Just this, Inspector. The whole matter hinges on Miss Smithers here. Bulstrode was anxious to see her. He hung about beneath her window until there was no one in the little square below. Miss Smithers was waiting to talk to her father in this very room about the delicate matter of her engagement to Mr. Fernchurch. She looked out of the window and saw Bulstrode. He was tapping about the base of the tower with a hammer, as she puts it. That is conclusive."
"How do you know this, Mr. Pons?" put in Professor Smithers.
"Because she told me so herself yesterday," said Pons evenly. "The sound had attracted her attention. She said that he looked up and may have seen her. She. turned away, quite properly, as she did not wish to be involved with him again."
"It is a pity you did not tell the police this, Miss Smithers," said the inspector quietly.
The girl flushed and lowered her eyes.
"I was afraid of what Father might say," she said. "And it did not seem really important."
"But it was important, Miss Smithers," Pons went on. "You heard some shouting in the street, I think you said; and then you father came in, in a temper, and slammed the door."
"That is so, Mr. Pons."
"Exactly."
Solar Pons looked round the sitting room in the deep silence which had fallen.
"It cannot be conclusively proved beyond a shadow of doubt but it is crystal-clear to my mind that what happened was this. Bulstrode, a vengeful giant with an ungovernable temper, wished to see his former fiancée, with a view to getting her back. He attracted her attention by the tapping of his hammer, and she came to the window. When he shouted to her, she turned away. Blind rage overcame him and he lost control. He hurled the heavy iron hammer at the girl, whether with the intention of killing her or maiming her, we shall never know. But impartial fate works in strange ways. By a weird series of coincidences Miss Smithers providently had gone from the window; his aim was bad, and the hammer struck the wall below the windowsill with tremendous force — the notch just there is more than an inch deep — and literally rebounded onto the head of the evildoer. The weight of the hammer alone, plus the height of the window from the ground and the tremendous velocity with which it was flung, was sufficient to shatter his skull and stretch him lifeless upon the ground."
There was a long silence, broken by Fernchurch, whose face bore a strange mixture of expressions. He went up to my friend and wrung him by the hand.
"Mr. Pons, you have saved my life."
Solar Pons chuckled, evidently satisfied with the effect he had created.
"How say you, Inspector?"
Inspector Fitzjohn came forward slowly, first looking toward the window and then at Fernchurch.
"Brilliant, Mr. Pons. I would be the first to admit it when we are wrong. We must needs have corroboration from our own people on that chip in the stonework beneath the window, of course, but I am convinced that what you have described is substantially correct. There are no other facts that fit. Mr. Fernchurch, you are an extremely fortunate young man."
"Well, Parker," said Solar Pons dryly. "Have you nothing to say?"
"I will reserve it for Praed Street, Pons," I said. "It will need more than a moment or two to do justice to your reasoning."
Solar Pons smiled as Miss Smithers and then her father came over and shook him by the hand.
"Perhaps we shall be left in peace now," said Smithers sourly as he took his leave.
"Well, Parker, I think our work here is concluded," said Solar Pons. "A decent lunch and then an afternoon train back to town. No doubt the inspector, Miss Smiths, and Mr. Fernchurch will join us at the inn. Would you have the goodness to book a table?"
8
"An interesting little exercise, Parker," said Solar Pons as Inspector Fitzjohn pulled the police car up in front of the imposing bulk of York Station in good time to catch the five o'clock train to London.