Quotation from: The Chessmen of Mars

Written by: Edgar Rice Burroughs

"You need have no fear of treachery," said Ghek "My only hope of
life lies in you."

"And if you fail me," Gahan admonished him, "I can promise you as
sure a death as even your king might guarantee you."

Ghek made no reply, but moved rapidly through the winding
subterranean corridors until Gahan began to realize how truly was
he in the hands of this strange monster. If the fellow should
prove false it would profit Gahan nothing to slay him, since
without his guidance the red man might never hope to retrace his
way to the tower and freedom.