After taking refuge in the Arrakis wasteland, the Zensunni Wanderers were little more than scavengers, and not very brave. Even on their most distant excursions to collect useful items, the nomads remained close to the rocks, avoiding the deep desert and the demon worms.

Long ago, after the Imperial chemist Shakkad the Wise had remarked on the rejuvenating properties of the obscure spice melange, there had been a small market for the natural substance among offworlders at the Arrakis City spaceport. However, the planet’s distance from popular spacing lanes had never made melange an economically attractive item. “An oddity, not a commodity,” one surly merchant had told Naib Dhartha. Still, spice was a staple in the food supply, and it must be gathered . . . but only on sands close to the rocks.

Dhartha led a party of six across a ridge of packed powder sand that held their footprints as if they were kisses in the dust. Loose white cloths around their heads and faces exposed only their eyes; their cloaks blew in the breeze, revealing equipment belts, tools, and weapons. Dhartha snugged the cloth higher over his nose to keep from breathing grit. He scratched the tattoo etched so painstakingly onto his cheek, then narrowed his eyes, always alert for danger.

No one thought to watch the clear morning skies until they heard a faint whistle growing quickly into a howl. To Naib Dhartha, it sounded like a woman who had just learned of her husband’s death.

Looking up, he saw a silvery bullet that tore through the atmosphere, then recognized the unexpected hum and whine of thrusters. A bubble-shaped object plummeted through the sky, spun about and see-sawed in the open air as if choosing a place to land. Quad engines slowed its descent. Then, less than a kilometer from where the scavenging party stood, the object slammed into the dunes like a fist thumping into the stomach of a dishonest merchant. A spray of dust and sand shot upward, embracing a tendril of dark soot.

The Naib stood stiffly and stared, while his men began to jabber excitedly. Young Ebrahim was as enthralled as Dhartha’s own son, Mahmad; both boys wanted to race out and investigate.

Mahmad was a good lad, respectful and cautious. But Dhartha had a low opinion of Ebrahim, who liked to tell stories and talk of imaginary exploits. Then there was the incident in which tribal water had been stolen, an unforgivable crime. Initially the Naib had thought two boys were involved, Ebrahim and Selim. But Ebrahim had been quick to disavow any responsibility and to point the finger at the other boy. Selim had seemed shocked at the accusation, but had not denied it.

In addition, Ebrahim’s father had stepped forward to make a generous deal with Dhartha to save his son . . . and so the orphan boy had received the ultimate sentence of banishment. Not much of a loss to the tribe. A Naib often had to make such difficult decisions.

Now, as the scavengers looked at Dhartha, their bright eyes glinting between folds of dirty white cloth, he knew he could not ignore the opportunity of this crashed ship, whatever it was. “We must go see this thing,” he called.

His men rushed across the sands, boisterous Ebrahim and Mahmad in the lead, hurrying toward the pillar of dust that marked the impact. Dhartha did not like to stray far from the sheltering rock, but the desert beckoned them toward a rich, alien treasure.

The nomads crested one dune, slid down the slipface, and scurried up another. By the time they reached the impact crater, they were all winded, panting hot breaths that were smothered by the cloths over their mouths. The Naib and his men stood on the high lip of excavated sand. Glassy smears of superheated silica had splattered like saliva on the ground.

Inside the pit lay a mechanical object the size of two men, with protrusions and components that hummed and moved, awakening now that it had landed. The carbon fiber-encased body still smoked from the heat of reentry. A spacecraft, perhaps?

One of Dhartha’s men stepped back, making a warding sign with his fingers. Overzealous Ebrahim, though, bent forward. The Naib put a hand on Mahmad’s left arm, cautioning his son. Let the foolish one take the risks.

The crashed pod was too small to carry passengers. The lights blinked brighter, and the probe’s sides opened like dragon wings to expose mechanical limbs, articulated claws, and complex machinery inside. Scanners, processors, engines of investigation and destruction. Mirrorlike power converters spread out in the glare of the sun.

Ebrahim slid down the churned sand at the edge of the pit. “Imagine what this would be worth at the spaceport, Naib! If I get to it first, I should receive the largest salvage share.”

Dhartha wanted to argue with the exuberant youth, but when he saw that no one— except for his own son— looked eager to join Ebrahim, he nodded. “If successful, you’ll get an extra share.” Even if the falling object was completely ruined, the nomads could work the pure metal for their own purposes.

The brash young man stopped halfway down the loose slope, looking suspiciously at the device, which continued to vibrate and thump. Flexible components extruded arms and legs, while strange lenses and mirrors rotated at the ends of flexible carbon fiber tentacles. The probe seemed to be assessing its surroundings, as if it didn’t comprehend where it had landed.

The machine paid no attention to the surreptitious humans, until Ebrahim dug a stone from the slumping side of the crater. He called out “Ai! Ai!” then hurled the rock. It struck the composite material of the probe’s side with an echoing clunk.

The mechanical lander froze, then turned its lenses and scanners toward the human standing all alone. Ebrahim hunched on bent knees in the yielding sand.

Blinding hot light erupted from one of the lenses. A gout of coherent fire engulfed Ebrahim and blew him backward in a crackling cloud of incinerated flesh and bones. A wad of smoldering garments struck the top of the crater, along with charred pieces of his hands and feet.

Mahmad screamed for his friend, and Dhartha immediately yelled for the men to retreat. They stumbled back down the outside of the crater and fled through the soft gully between dunes. Half a kilometer away, safe, they climbed to a sandy crest high enough that they could look back toward the pit. The men prayed and made superstitious gestures, and Dhartha raised his clenched right fist. Foolish Ebrahim had drawn the attention of the mechanical thing and had paid with his life.

From a distance, the would-be scavengers watched. The crashed probe paid them no further heed. Instead, with thumping and clattering, the machine seemed to be assembling itself, building structures around its core. Scooping hands drew sand into a resource-production hopper in its belly and extruded glasslike rods that it used for structural supports. The machine added new components, building itself larger, and finally began digging its way out of the pit. It pounded and hammered, making a great deal of racket.

Dhartha remained perplexed. Though he was a leader, he had no idea what to do. Such a thing was beyond his ken. Perhaps someone at the spaceport would know, but he hated to rely on outworlders. Besides, this thing might be valuable, and he didn’t want to surrender his salvage.

“Father, look.” Mahmad gestured toward the wasteland of sand. “See, that machine demon will pay for killing my friend.”

Dhartha saw the telltale ripple, the stirring of a behemoth beneath the sands. The crashed probe continued its pounding, rhythmic motion with a clattering of components, oblivious to its surroundings. The assembled mechanism raised itself, a monstrous composite of crystalline materials and silica struts reinforced by carbon-fiber beams converted from its own hull and support girders.

The sandworm came in fast, tunneling just beneath the surface until its head rose up. The mouth was a huge shovel larger than the impact crater.

The robotic probe waved its sensor arms and weapons lenses, sensing it was being attacked, but not understanding how. Several white-hot blasts of fire penetrated the loose ground.

The worm swallowed the mechanical demon whole. Then the sinuous desert creature burrowed beneath the dust again like a sea serpent seeking deeper waters. . . .

Naib Dhartha and his men remained petrified on the dunes. If they turned and ran now, their vibrations would call the sandworm back for another meal.

Soon enough, they saw the worm trail heading outward, returning to the deep desert. The crater was gone, along with all evidence of the mechanical construction. Not even a scrap of foolish Ebrahim’s body remained.

Shaking his head with its long black ponytail, Dhartha turned to his shocked companions. “This will make a legendary story, a magnificent ballad to be sung in our caves in the dark of night. . . .” He drew a deepbreath and turned around. “Though I doubt anyone will ever believe us.”