What does he want of the other men his deputies have enslaved? Why did
he poison the Service men? And why--especially why--do two honorable
men, officials of two important nations, want to tip off the United
States Government about the ghastly business? What's it got to do with
our nation?"

Bell flung away his cigarette.

"That last question has occurred to me too," he observed, and
carefully repressed a slight shiver. "I have made a guess, which is
probably insane. I'm going to see Ribiera this afternoon."

"He already suspects you know too much," said Jamison without
expression.

"I am"--Bell managed the ghost of a mirthless smile--"I am
uncomfortably aware of it. And I may need an antidote as badly as
Ortiz. If I do, and can't help myself, I'll depend on you."

* * * * *

Jamison growled.

"I simply mean," said Bell very quietly, "that I'd really rather not
be--er--left alive if I'm mad. That's all. But Ortiz knew what was the
matter with him before he got bad off. I know it's a risk. I'm
goose-flesh all over. But somebody's got to take the risk. The guess
I've made may be insane, but if it's right one or two lives will be
cheap enough as a price for the information. Suppose you chaps turn
around and take me to Ribiera's house?"

There was a long pause. Then Jamison spoke in Portuguese to his
companion. The taxi checked, swerved, and began to retrace its route.

"You're a junior in the Trade," said Jamison painstakingly. "I can't
order you to do it."

Bell fumbled with his cigarette case.

"The Trade doesn't exist, Jamison," he said dryly. "And besides,
nobody gives orders in The Trade. These are only suggestions. Now shut
up a while. I want to try to remember some consular reports I read
once, from the consul at Puerto Pachecho."

"What?"

"The consul there," said Bell, smiling faintly, "was an amateur
botanist. He filled up his consular reports with accounts of native
Indian medicinal plants and drugs, with copious notes and clinical
observations. I had to reprove him severely for taking up space with
such matters and not going fully into the exact number of hides, wet
and dry, that passed through the markets in his district. His
information will be entirely useless in this present emergency, but
I'm going to try to remember as much of it as I can. Now shut up."

* * * * *

When the taxi swung off the Biera Mar to thread its way thr