be required
during the entire ten-day cycle, and that would mean that at some time
each night one of these doors would have to be opened and shut to allow
the watcher to be relieved. And if the emptying of the props were done
at night how were they to ensure that this operation should not coincide
with the visit of the relief? And this was all presupposing that a
suitable hiding place could be found inside the building in such a
position that from it the operations in question could be overlooked.

Here no doubt were pretty serious obstacles, but even were they all
successfully overcome it did not follow that they would have solved the
problem. The faked props might be loaded up and forwarded to some other
depot, and, if so, this other depot might be by no means easy to find.
Further, if it were found, nocturnal observation of what went on within
would then become necessary.

It seemed to the friends that all they had done up to the present would
be the merest child's play in comparison to what was now required.
During the whole of that day and the next they brooded over the problem,
but without avail. The more they thought about it the more hopeless it
seemed. Even Hilliard's cheery optimism was not proof against the wave
of depression which swept over him.

Curiously enough it was to Merriman, the plodding rather than the
brilliant, that light first came. They were seated in the otherwise
empty hotel lounge when he suddenly stopped smoking, sat motionless for
nearly a minute, and then turned eagerly to his companion.

"I say, Hilliard," he exclaimed. "I wonder if there mightn't be another
way out after all--a scheme for making them separate the faked and
the genuine props? Do you know Leatham--Charlie Leatham of Ellerby,
somewhere between Selby and Boughton? No? Well, he owns a group of mines
in that district. He's as decent a soul as ever breathed, and is just
rolling in money. Now,--how would it do if we were to go to Charlie and
tell him the whole thing, and ask him to approach these people to see if
they would sell him a cargo of props--an entire cargo. I should explain
that he has a private wharf for lighters on one of those rivers up
beyond Goole, but the approach is too shallow for a sea-going boat. Now,
why shouldn't he tell these people about his wharf, saying he had heard
the Girondin was shallow in the draught, and might get up? He would then
say he would take an entire cargo on condition that he could