,
was the irony of the situation. We both held the clue to that mad hatred
of Manderson's which Marlowe found so mysterious. We knew of his jealous
obsession; which knowledge we withheld, as was very proper, if only in
consideration of Mabel's feelings. Marlowe will never know of what he
was suspected by that person. Strange! Nearly all of us, I venture to
think, move unconsciously among a network of opinions, often quite
erroneous, which other people entertain about us. With regard to
Marlowe's story, it appeared to me entirely straightforward, and not, in
its essential features, especially remarkable, once we have admitted, as
we surely must, that in the case of Manderson we have to deal with a
more or less disordered mind. It was Mr. Bunner, I think you said, who
told you of his rooted and apparently hereditary temper of suspicious
jealousy. When the pressure of his business labors brought on mental
derangement, that abnormality increased until it dominated him
entirely."

Trent laughed loudly. "Not especially remarkable!" he said. "I confess
that the affair struck me as a little unusual."

"Only in the development of the details," argued Mr. Cupples. "What is
there abnormal in the essential facts? A madman conceives a crazy
suspicion; he hatches a cunning plot against his fancied injurer; it
involves his own destruction. Put thus, what is there that any man with
the least knowledge of the ways of lunatics would call remarkable? Turn
now to Marlowe's proceedings. He finds himself in a perilous position
from which, though he is innocent, telling the truth will not save him.
Is that an unheard-of situation? He escapes by means of a bold and
ingenious piece of deception. That seems to me a thing that might happen
every day and probably does so." He attacked his now unrecognizable
mutton.

"I should like to know," said Trent after an alimentary pause in the
conversation, "whether there is anything that ever happened on the face
of the earth that you could not represent as quite ordinary and
commonplace, by such a line of argument as that. You may say what you
like, but the idea of impersonating Manderson in those circumstances was
an extraordinarily ingenious idea."

"Ingenious--certainly!" replied Mr. Cupples. "Extraordinarily so--no! In
those circumstances (your own words) it was really not strange that it
should occur to a clever man. It lay almost on the surface of the
situation. Marlowe was famous for his imita