"It was a woman's voice," he answered.
"Great heavens!" I muttered—"what does it all mean?"
That the evidence of the cabman when he was discovered and of the carter who had taken the box from the garage to the docks, and (for it was possibly the same man) who had first delivered it at the Red House, would but tighten the net about Isobel, whom I knew to be innocent, I felt assured.
"Gatton," I said, "this case appears to me to resolve itself into a deliberate conspiracy of which the end was not the assassination of Sir Marcus, but the conviction of Miss Merlin!"
Gatton looked at me with evident complexity written all over him.
"I begin to think the same," he confessed. "This business was never planned and carried out by a woman, I'll swear to that. There is a woman concerned in it, for at every point we come upon evidence of her voice issuing the mysterious instructions; but she is not alone in the matter. Already the intricacy of the thing points to a criminal of genius. When we know the whole truth, if we ever do, that the crime was planned by a man of amazing, if perverted, intellect, will be put beyond dispute, I think."
"What is puzzling me, Gatton," I said, "is the connection existing between the incidents which took place in this garage and those, unknown at present, which took place in the furnished room in the Red House."
"Obviously," replied Gatton, "a supper for two had been prepared, and that one of those two was the late Sir Marcus is perfectly obvious. That he expected the other to be Miss Merlin is at least suggested by the presence of her photograph in the room; for you will have noticed that it is the only photograph there."
"Nevertheless," I said firmly, "I am positive that no one would be more surprised than herself to learn of its presence."
"And as I have already said," replied Gatton, "I am rapidly coming round to your way of thinking. But even if I were quite sure of it the evidence at the moment is all the other way, you will admit. As to the connection between this garage and the interrupted supper party (for obviously it was interrupted) this it must be my business to find out."