At Worcester we had still a long wait for the argosy that was
causing so much anxiety and danger. It was long after the time
scheduled that we left finally, on our return journey, late at
night.

Ahead of us went a dummy pilot-train to be sacrificed if any
bridges or trestles were blown up or if any new attempts were made
at producing artificially broken rails. We four established
ourselves as best we could in a car in the center of the treasure-
train, with one of the armed guards as company. Mile after mile we
reeled off, ever southward and westward.

We must have crossed the State of Connecticut and have been
approaching Long Island Sound, when suddenly the train stopped
with a jerk. Ordinarily there is nothing to grow alarmed about at
the mere stopping of a train. But this was an unusual train under
unusual circumstances.

No one said a word as we peered out. Down the track the signals
seemed to show a clear road. What was the matter?

"Look!" exclaimed Kennedy, suddenly.

Off a distance ahead I could see what looked like a long row of
white fuses sticking up in the faint starlight. From them the
fresh west wind seemed to blow a thick curtain of greenish-yellow
smoke which swept across the track, enveloping the engine and the
forward cars and now advancing toward us like the "yellow wind" of
northern China. It seemed to spread thickly on the ground, rising
scarcely more than sixteen or eighteen feet.