Resonant booming shook the sand around them.
Paul lurched sideways two steps.
"Boom! Boom!"
"Drum sand!" Jessica hissed.
Paul recovered his balance. A sweeping glance took in the sand around them, the rock escarpment perhaps two hundred meters away.
Behind them, he heard a hissing - like the wind, like a riptide where there was no water.
"Run!" Jessica screamed. "Paul, run!"
They ran.
Drum sound boomed beneath their feet. Then they were out of it and into pea gravel. For a time, the running was a relief to muscles that ached from unfamiliar, rhythmless use. Here was action that could be understood. Here was rhythm. But sand and gravel dragged at their feet. And the hissing approach of the worm was storm sound that grew around them.
Jessica stumbled to her knees. All she could think of was the fatigue and the sound and the terror.
Paul dragged her up.
They ran on, hand in hand.
A thin pole jutted from the sand ahead of them. They passed it, saw another.
Jessica's mind failed to register on the poles until they were past.
There was another - wind-etched surface thrust up from a crack in rock.
Another.
Rock!
She felt it through her feet, the shock of unresisting surface, gained new strength from the firmer footing.
A deep crack stretched its vertical shadow upward into the cliff ahead of them. They sprinted for it, crowded into the narrow hole.
Behind them, the sound of the worm's passage stopped.
Jessica and Paul turned, peered out onto the desert.
Where the dunes began, perhaps fifty meters away at the foot of a rock beach, a silver-gray curve broached from the desert, sending rivers of sand and dust cascading all around. It lifted higher, resolved into a giant, questing mouth. It was a round, black hole with edges glistening in the moonlight.
The mouth snaked toward the narrow crack where Paul and Jessica huddled. Cinnamon yelled in their nostrils. Moonlight flashed from crystal teeth.
Back and forth the great mouth wove.
Paul stilled his breathing.
Jessica crouched staring.
It took intense concentration of her Bene Gesserit training to put down the primal terrors, subduing a race-memory fear that threatened to fill her mind.
Paul felt a kind of elation. In some recent instant, he had crossed a time barrier into more unknown territory. He could sense the darkness ahead, nothing revealed to his inner eye. It was as though some step he had taken had plunged him into a well . . . or into the trough of a wave where the future was invisible. The landscape had undergone a profound shifting.
Instead of frightening him, the sensation of time-darkness forced a hyper-acceleration of his other senses. He found himself registering every available aspect of the thing that lifted from the sand there seeking him. Its mouth was some eighty meters in diameter . . . crystal teeth with the curved shape of crysknives glinting around the rim . . . the bellows breath of cinnamon, subtle aldehydes . . . acids . . .
The worm blotted out the moonlight as it brushed the rocks above them. A shower of small stones and sand cascaded into the narrow hiding place.
Paul crowded his mother farther back.
Cinnamon!
The smell of it flooded across him.
What has the worm to do with the spice, melange? he asked himself. And he remembered Liet-Kynes betraying a veiled reference to some association between worm and spice.
"Barrrroooom!"
It was like a peal of dry thunder coming from far off to their right.
Again: "Barrrroooom!"
The worm drew back onto the sand, lay there momentarily, its crystal teeth weaving moonflashes.
"Lump! Lump! Lump! Lump!"
Another thumper! Paul thought.
Again it sounded off to their right.
A shudder passed through the worm. It drew farther away into the sand. Only a mounded upper curve remained like half a bell mouth, the curve of a tunnel rearing above the dunes.
Sand rasped.
The creature sank farther, retreating, turning. It became a mound of cresting sand that curved away through a saddle in the dunes.
Paul stepped out of the crack, watched the sand wave recede across the waste toward the new thumper summons.
Jessica followed, listening: "Lump . . . lump . . . lump . . . lump . . . lump . . ."
Presently the sound stopped.
Paul found the tube into his stillsuit, sipped at the reclaimed water.
Jessica focused on his action, but her mind felt blank with fatigue and the aftermath of terror. "Has it gone for sure?" she whispered.
"Somebody called it," Paul said. "Fremen."
She felt herself recovering. "It was so big!"
"Not as big as the one that got our 'thopter."
"Are you sure it was Fremen?"
"They used a thumper."
"Why would they help us?"
"Maybe they weren't helping us. Maybe they were just calling a worm."
"Why?"
An answer lay poised at the edge of his awareness, but refused to come. He had a vision in his mind of something to do with the telescoping barbed sticks in their packs - the "maker hooks."
"Why would they call a worm?" Jessica asked.
A breath of fear touched his mind, and he forced himself to turn away from his mother, to look up the cliff. "We'd better find a way up there before daylight." He pointed. "Those poles we passed - there are more of them."
She looked, following the line of his hand, saw the poles - wind-scratched markers - made out the shadow of a narrow ledge that twisted into a crevasse high above them.
"They mark a way up the cliff," Paul said. He settled his shoulders into the pack, crossed to the foot of the ledge and began the climb upward.