or he had
discovered the key which alone could unlock the mystery, or consign it
forever to the realms of the unfathomable.

A week later the two men came suddenly upon a clearing in the forest.

In the distance were several buildings surrounded by a strong palisade.
Between them and the enclosure stretched a cultivated field in which a
number of negroes were working.

The two halted at the edge of the jungle.

Tarzan fitted his bow with a poisoned arrow, but D'Arnot placed a hand
upon his arm.

"What would you do, Tarzan?" he asked.

"They will try to kill us if they see us," replied Tarzan. "I prefer
to be the killer."

"Maybe they are friends," suggested D'Arnot.

"They are black," was Tarzan's only reply.

And again he drew back his shaft.

"You must not, Tarzan!" cried D'Arnot. "White men do not kill
wantonly. MON DIEU! but you have much to learn.

"I pity the ruffian who crosses you, my wild man, when I take you to
Paris. I will have my hands full keeping your neck from beneath the
guillotine."

Tarzan lowered his bow and smiled.

"I do not know why I should kill the blacks back there in my jungle,
yet not kill them here. Suppose Numa, the lion, should spring out upon
us, I should say, then, I presume: Good morning, Monsieur Numa, how is
Madame Numa; eh?"

"Wait until the blacks spring upon you," replied D'Arnot, "then you may
kill them. Do not assume that men are your enemies until they prove
it."

"Come," said Tarzan, "let us go and present ourselves to be killed,"
and he started straight across the field, his head high held and the
tropical sun beating upon his smooth, brown skin.

Behind him came D'Arnot, clothed in some garments which had been
discarded at the cabin by Clayton when the officers of the French
cruiser had fitted him out in more presentable fashion.

Presently one of the blacks looked up, and beholding Tarzan, turned,
shrieking, toward the palisade.

In an instant the air was filled with cries of terror from the fleeing
gardeners, but before any had reached the palisade a white man emerged
from the enclosure, rifle in hand, to discover the cause of the
commotion.

What he saw brought his rifle to his shoulder, and Tarzan of the Apes
would have felt cold lead once again had not D'Arnot cried loudly to
the man with the leveled gun:

"Do not fire! We are friends!"

"Halt, then!" was the reply.

"Stop, Tarzan!" cried D'Arnot. "He thinks we are enemies."

Tarz