de a verbal offer to lease the Red House for a period
of twelve months. A foreigner, who in lieu of the usual references,
was prepared to pay the annual rent in advance. As the Red House, to
use an Irishism, was regarded as something of a white elephant, the
agent was interested, apparently; and when on the following day the
sum agreed upon arrived by post, he did not demur about delivering the
keys to the prospective lessee, who desired to take certain
measurements in regard to carpets and so forth."

"Wait a moment," I interrupted; "to whom did he deliver these keys?"

"To a district messenger who called for them, as the agent had been
advised that one would do."

"Very well. What then?"

"That is all that the agent had to say."

"What, that is all?"

"Substantially there is nothing more. It is quite evident that the
sole intention of this unknown lessee was to secure possession of the
house for the purpose of the crime only."

"Do you mean that from first to last no one but the district messenger
appeared in the matter?"

"No one," Gatton assured me, "and the rent, payment of which quite
disarmed the agent of course, was sent in the form of Treasury notes
and not by check."

"But surely some name, some address, must have been given?"

"A name was given," replied Gatton, "and a hotel address, but
confirmation of their accuracy was never sought, after the receipt of
the money."

"And the voice on the telephone?"

Again I saw that odd expression creep over Gatton's face, and:

"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