in from the car's smoking
compartment, and sat down wearily across from Blake. He pushed his big
feet up on the chair beside Blake.

"What do you make of it?" he asked.

Blake pointed to the paper silently and O'Toole picked it up. He read
quickly, his eyes darting from side to side of the page. His face grew
purple.

"They certainly pulled a fast one," he growled. "A whole train missing,
with the owner of the line and his daughter on it. I never stopped to
think what that might mean when the papers got hold of it."

"Nor I," Blake admitted. "But Harror did, and if I'm not mistaken,
someone with a lot more brains than Harror had the same idea. This thing
was carefully planned, O'Toole, but there are two points that the Silver
Masks overlooked."

O'Toole looked at him questioningly.

"One was they didn't expect you and me to cause the trouble we're going
to," Blake went on, "and the other is Wade. He's around somewhere. He
may help us out at the right time."

O'Toole spat disgustedly.

"_We_ can cause trouble if we ever get out of here," he admitted. "I'm
not so sure of Wade."

A shaft of light cut in through the window suddenly, blinding them both.

They stared out with wide eyes. A murmur of voices from the car told
them that the others were awake, and also impressed by what they saw.

Mono 6 was in a great cavern. Great black granite walls towered high
above. The mono train had evidently entered the cave slowly and slipped
between a long row of huge boulders that held it upright. The cave was a
graveyard of mono cars. They lay across the full width of its floor,
dismantled and torn apart for whatever value they had to offer.

For the first time Blake realized just how large operations had been;
just how close the Silver Masks were to ruining the industry Ferrell had
painstakingly built up.

Men appeared from a long row of doors worked into the cliff side. They
all looked alike in the black suits and glittering silver masks. Tools
of every description had made their appearance. Beyond the doors from
whence they had come must be a complete set of living quarters with
access to the outside world.

Common sense told Blake that the entrance through which Mono 6 had
arrived was now carefully sealed. If he was to solve the mystery of
Grudge Harror's plans and make escape possible, it would be necessary to
go through those doors. Harror himself was there somewhere, and Blake's
fists ached to meet the man al