It was preposterous to think that either of the twins was guilty of the crime. Helen's devotion to Jimmie, her insistence upon an autopsy being held indicated her innocence. She had stated at the inquest that she had not known the burglar's identity; Kent paused as the thought occurred to him—the twins had swapped identities on the witness stand, and therefore Helen had not been called upon to answer that question! To the best of his recollection she had only been asked if she had recognized Jimmie in the court room and not at her home. But Helen it was who had summoned Officer O'Ryan on discovering the burglar and had him arrested. She surely would never have done so had she guessed his identity.
As for Barbara McIntyre—Kent's heart beat faster at thought of the girl he loved so well. Circumstantial evidence had seemed for a time to involve her in the crime. Grimes' outrageous insinuation that he had been assaulted on account of confiding to her that the box of aconitine pills had been left on the hall table where any one could get them, was the outcome of his battered condition. When physical strength returned, the butler would forget his hallucinations. The handkerchief with its embroidered letter “B,” used by Jimmie to inhale the fumes from his amyl nitrite capsules, was finally traced to its rightful owner—Mrs. Brewster.
And Mrs. Brewster was due in his office within a very short time. Kent's square jaw became more pronounced; she should not leave until she had either confessed her connection with Turnbull's death, or established her innocence. Surely it would be easy for Mrs. Brewster to do so, but—aconitine had been prescribed for her; she was familiar with the poison, she had it at hand, she went to the police court, and kept her trip a secret, and she had laughed when Jimmie was carried dying from the court room. But what motive could have inspired her to murder Jimmie? Was he an old lover—Kent, unable to keep quiet any longer, rose and paced up and down the office, stopping a moment to glance out of the window. As he passed the safe he saw the door was ajar. Kent paused abruptly. Who had opened the safe?
Crossing to the outer office he looked around; no one was there. It flashed into Kent's mind that he had seen Rochester's light top coat and walking stick in the coat closet as he hung up his hat on his arrival, and he again opened the closet door. The coat and stick were still there; so Rochester had come to the office immediately after leaving him, and carelessly left the safe open! Kent smiled in spite of his vexation; the act was typical of his eccentric partner.
Going back to his own office Kent opened the safe and glanced inside. The pigeon holes and compartments appeared untouched, except the door of one small compartment on Rochester's side. An envelope was wedged in such a manner that the small door would not shut and that had prevented the closing of the outer safe door.
Kent, preparatory to shutting the safe, drew out the envelope intending to place it in another pigeon-hole where there was more room. As he turned the envelope over he was thunderstruck to recognize it as the one which Helen McIntyre had placed in the safe on Wednesday morning. He had last seen the envelope lying on the table in the smoking porch of the Club de Vingt, from whence it had mysteriously disappeared, and now it was back again in Rochester's safe!
Had it ever been missing from the safe? The question forced itself on Kent as he returned to his chair, envelope in hand, and sat down before his desk. He had accepted Detective Ferguson's statement that he had removed the envelope from the safe, and therefore had never looked in the compartment where Helen had put it to verify its disappearance.
Ferguson had removed it, Kent concluded as he examined the envelope with more care; it was the identical one, unaddressed, with the same red seal holding down the flap. The same red seal, but with a difference—a corner was missing.
Kent stared at the seal for a moment in doubt, then his fingers sought his vest pocket and fumbled about for a minute. Taking out Mrs. Brewster's check, he laid it on the desk alongside the envelope, unfolded it, and picked out a piece of red sealing wax which had slid inside the check. Kent placed the red wax on the broken section of the seal—it fitted exactly, forming a perfect letter “B.”
Kent sat in dumbfounded silence, regarding the red seal and the envelope. The piece of wax broken off from the seal had caught on his coat sleeve when he had been in the Venetian casket in the library at the McIntyre house. It was proof positive that not only he had been in the casket, but the sealed envelope also. Helen McIntyre had left the envelope in his care. Mrs. Brewster and Colonel McIntyre had both been present when the envelope was stolen from him. Which of them had taken it? Which one had afterwards secreted it in the Venetian casket? And which had brought it back to the safe in his office?