reen ray, or
whatever you call it, is simply a manifestation of some strange
electrical combination in the air."

"I'm afraid we shall have to leave it at that," I said with an
elaborate sigh of regret.

"Not when you have Mr. Burnham's distinguished powers of deduction to
assist you, surely, Mr. Ewart?" said Hilderman, and waited for an
answer.

"Flukes are not very consistent things, I fear," Dennis supplied him
readily, "and if we are to make any progress we shall hardly have time
for idle speculation."

"Fortune might continue to favour you," the American persisted. "Don't
you think it's worth trying?"

"I'm afraid not," said Dennis, with a laugh that added emphasis and
conviction to his statement.

"By the way," Myra suggested, "I don't know if anybody would care for
a whisky and soda or anything. I won't have drinks served in here, but
if anybody would like one, you know where everything is, Ron. I always
say if anyone wants a drink in my den they can go and get it, and
then I know they really like being in the den. You see I'm a woman,
Mr. Hilderman," she laughed.

"I must say I think the idea of refreshment would not enter the head
of anyone who had the pleasure of your company here, Miss McLeod,
unless you suggested it yourself."

We laughed at the rather heavy compliment, and I went into the
dining-room to fetch the decanters, syphons and glasses.

"I'll help you to get them," called Dennis, and followed me out of the
room.

"Well?" I asked as soon as we reached the other room. "What do you
make of it?"

"I'm not sure," Dennis admitted. "I'm puzzled. I shouldn't be
surprised if he turned out to be a Government secret service man
keeping an eye on Fuller-von-Guernstein, and that when he has quite
made up his mind that the mystery of the green ray is connected with
his own business he will show his hand."

"Something of the same sort occurred to Garnesk," I said. "Well,
at present we'd better avoid suspicion and go back before he thinks
we're holding a committee meeting."

So I led the way to the den. I was walking carefully and slowly,
because I was unaccustomed to carrying trays of glasses and things,
and consequently I made no noise. I pushed the door open with my
shoulder, Dennis following with a couple of syphons, and as I did so
I chanced to glance upwards.

In a large mirror which hung over the fireplace I saw the reflection
of Hilderman's face, knitted in a fierce frown, gazing inten