Our idyll was interrupted by a ring at the doorbell and then we heard an altercation in the hallway below; an excited female voice was opposed in a duet with the more placid tones of Mrs. Johnson. There followed scrambling footsteps on the stairs, our door was flung open unceremoniously and a panting, wild-eyed woman stood there, her black eyes flashing with anger and outrage as she stared first at me and then at my companion.
“Mr. Pons! Mr. Solar Pons! How dare you send me such a message! You have quite upset my work at the laboratory.” Solar Pons rose from his chair with a smile.
“The truth often does strike like a blow, Miss Thornton. Will you not close the door and sit down? You will find a comfortable chair yonder.”
The imperious, dark-haired woman slammed the door back in its frame with a crash that seemed to shake the building. She stamped her foot as she stared at Pons.
“I will know what this outrageous note means before I leave this house!”
She flung a sheet of paper toward him and it came to rest near the foot of my chair. Solar Pons smiled thinly.
“You would do well to sit, Miss Thornton. I really do advise it. And Dr. Parker here, as a medical man, would prescribe the relaxed position as a tonic for the nerves.”
The angry woman paused and made an impatient movement with her hand as though she would have flung something at my companion. Then she apparently thought better of it and sank sullenly into the chair indicated. I had picked up the paper and held it out to Pons. He merely gestured to me to read it.
It said: Dear Miss Thornton, If you wish to tell me all the facts about the murder of Mrs. Tregorran I shall be at my quarters at 7B Praed Street at eight o’clock this evening. I am in possession of the true circumstances and if you do not answer my summons you will have to deal directly with the official police.
Truly yours,
Solar Pons.
I put the sheet down on our table and looked across at the white, compressed face of Celia Thornton. She was a little more composed now.
“I am waiting, Mr. Pons,” she said grimly.
“I shall not keep you, Miss Thornton, and will come directly to the paint. We have heard from Mr. Tregorran that you and he had been intimate for some while, but that he had become reconciled with his wife. Jealousy is a great distorter of human relations.”
The woman opposite us had a strange smile on her taut features.
“I have not denied my relationship with Tregorran,” she said. “I gave a statement to the police yesterday.”
“I am well aware of that, Miss Thornton. What I am saying here today is that you know a great deal more than you have stated about Mrs. Tregorran’s death and the charge of murder that is now hanging over her husband.”
Celia Thornton tossed her head and looked from Pons to me and then back to my companion again.
“The implication is preposterous, Mr. Pons. You will have to do better than that.”
“I intend to,” said Solar Pons calmly.
“Let us just recall the sequence of events. Mrs. Tregorran is found strangled in a locked studio, her husband nearby, incoherent and unaware of what has happened. I questioned the unfortunate man yesterday and I am convinced that he is speaking the truth. What we are left with is something more complicated.”
Celia Thornton sat watching Solar Pons with glittering eyes but said nothing.
“The first thing that struck me about the case was a locked door without a key,” Pons went on. “That was extremely significant and I commended it to you, Parker. I will now suggest the possible sequence of events and Miss Thornton will no doubt correct me if I am wrong. Tregorran had an unhappy marriage and had formed an association with you. But when he said that he was becoming reconciled to his wife, you became extremely jealous and there were violent quarrels. We have that from Tregorran himself. You concocted an elaborate scheme for revenge that would punish both the wife whom you hated and your lover also.”
“Prove it!” Miss Thornton snapped.
“I am endeavouring so to do,” said Solar Pons equably. “Your love had turned to hate and you would stop at nothing to strike back at your former lover and the obstacle to your happiness. In your liaison with Tregorran you had obviously visited his studio. He has not told me so but I infer it as it is central to my theory.”
“I knew the studio,” the woman said with a curious smile. “The fact is not in question and easy enough to check. I admit it.”
Solar Pons inclined his head gravely.
“Very well, then. You knew the studio and the lay-out of the house. You had your own keys to the doors. On the day of the murder you went to the house and entered by the archway unseen. It is easy enough to do. Instead, however, of entering the studio by the staircase entrance, you opened the inner door to the corridor, of which you retained a key. You stationed yourself in the angle of the corridor and waited until Relph brought Tregorran’s lunch-tray.
“When he had tapped on the door and withdrawn you quickly went to the table, removed the plate of soup and the dessert. To do that — and you thought you had not very much time — you removed the bottle of lager and put it down on the table. I know that because I have seen the marks in the dust and it puzzled me at first why this should be so. The explanation then became clear to me. You put the food within the large vase used as an umbrella stand in the annexe.”
Celia Thornton’s eyes were very bright.
“Preposterous! Why should I wish to do that?”
Solar Pons held up his hand.
“I am just coming to that. You returned to the table and put the beer bottle and tumbler back on the tray. Beside it you placed your specially prepared sandwich.”
It was very quiet in the room now and I looked at Pons, my puzzlement evident on my features.
“You then resumed your vigil at the end of the corridor. When Tregorran had taken the lunch-tray back into the studio, which was not for some time, you crept back down the corridor. You quietly locked the door and took the key away.”
“Why was that, Pons?”
“Because, Parker, there had to be time for Miss Thornton’s plan to work and she did not want the sitting interrupted. It was also vital for the scheme’s success that Tregorran should be seen by witnesses to be sane and in possession of himself.”
“I am afraid I do not see…”
“Tut, Parker, Miss Thornton herself will give us the ingenious explanation in a moment or two.”
Our visitor drew herself up, little spots of red blazing on her cheeks.
“I find your questions offensive, your implications odious and your conclusions entirely erroneous, Mr. Pons.”
Solar Pons drew reflectively on his pipe, little stipples of fire making patterns on his thin, ascetic features.
“Indeed. You face it out well enough, Miss Thornton, but you know in your heart that your cruel and ingenious scheme has been discovered. Let us just take things a step further. When I first visited the studio I did not, of course, know of your possible involvement in the matter. When I learned that you were a brilliant experimental chemist things began to fall into place.”
“I see, Pons,” I began, light dawning in dark places.
“No doubt, Parker,” said Solar Pons crisply.
“I had noted that the lager was a special export brand, sealed with foil and a metal cap. That indicated to me that it was unlikely anything could have been introduced into the beer. But it could have acted as a catalyst for something else that should not have been in the food. Where I made my big mistake was in not detecting the substitution earlier. I had asked Mrs. Mandeville and Relph about Tregorran’s lunch but none of us had thought to mention its composition. And then there was the matter of the missing key. You showed considerable courage in that respect, as indeed, throughout this dreadful business.”