He stood looking around, caressing the handle of the whip with his fingers. On three sides towered walls and trees and vines, inextricable and undefined; where walls ended and trees began it was impossible to say, for the growth of two hundred jungle years is not to be lightly set aside by a few Arabs in a week's time. Jenson sank down where he stood, cowed into silence by the silence around.
Suddenly, as if the echoes of the doctor's words had worked through the interstices of the leafy roof, a great burst of shrill chattering arose somewhere overhead.
Hammer jumped, startled; at the same instant two or three white objects shot down from nowhere, apparently. Two burst into shreds, the other struck a mossy wall and rebounded to the feet of Krausz, who leaped back in alarm.
One half-stifled shriek burst from the first askari and stilled the clamour above. Sara Helmuth stared at the thing, as did everyone else, her face very pale; and Hammer knew, at last, that Omar ibn Kasim had spoken truth indeed—for the object was a skull.
An oath from Krausz recalled the frightened askaris to their vigilance. He stood mopping his brow and staring from the unbroken skull to the trees above, and, as Hammer glanced up, he saw one or two dark forms flitting about the top of the nearest wall and vanishing in the trees.
"Monkeys!" exclaimed Sara Helmuth, her eyes unnaturally large, but her voice firm. "Are you afraid of monkeys and skulls, Herr Doctor?"
For answer Krausz snorted and picked up the skull. He flung it away instantly.
"Pah! It iss mouldy—it hass been the ground in. Monkeys—pigs of scavengers! Yess, thiss iss the place."
For a moment he stood silent. Then, for the gruesome thing must have wakened the depths of him, he swiftly changed the whip to his left hand, drew a revolver with the other, and turned on the group behind him.
Hammer started at the change in the man. His great brow was mottled, as were his cheeks, save for the panting band of muscle that stood out deep red, and his black eyes gleamed with something that was near akin to ferocity. Never had Hammer seen such a face on a man, and now, for the first time, a strange alarm stirred within him.