In the first-class coach I found Lieutenant Long, towering so far
above all his surroundings as to have been easily recognized even
had he not been in uniform. Beside him sat Corporal Castillo of
the "plain-clothes" squad, a young man of forty, with a high
forehead, a stubby black mustache, and a chin that was decisive
without being aggressive.

"Now here's the Captain's idea," explained the Lieutenant, as the
train swung away around Ancon hill, "We'll have to take turns
mounting guard over them, of course. I'll have to talk Spanish,
and nobody'd have to look at Castillo more than once to know he
was born up in some crack in the Andes."--Which was one of the
Lieutenant's jokes, for the Corporal, though a Colombian, was as
white, sharp-witted, and energetic as any American on the Zone.
--"But no one to look at him would suspect that Fr--French, is
it?"

"Franck."

"Oh, yes, that Franck could speak Spanish. We 'll do our best to
inflate that impression, and when it comes your turn at guard-
mount you can probably let several little things of interest drift
in at your ears."

"I left headquarters before the Captain had time to explain," I
suggested.

"Oh!" said the Lieutenant. "Well, here it is in a spectacle-case,
as our friend Kipling would put it. We're on our way to Culebra
Island. There are now in quarantine there three men who arrived