Wally West ran with a vial of cure strapped to his chest, and the heat was killing his speed. A sandstorm was swallowing cities behind him. He had to reach the last settlement before the sand did. But the heatwave turned the air to soup. Each step came slower than the last. His legs, which once blurred, now dragged like wet rope. Sweat stung his eyes. His red suit clung to him. The lightning bolt on his chest felt like a brand. He pushed harder, but his vision swam. Numbers scrolled in his head, the math he always ran. At this pace, he would collapse in minutes. The settlement was too far. The storm was too close. He needed to cool down. Fast. Or the cure would die in the sand with him. Then he saw it. A small wooden shelter sat alone on the flat ground. Its sloped roof threw a wedge of shade. Wally stumbled toward it and fell through the open doorway. The dark inside hit him like water. He gasped and pressed his back to the cool planks. "You look half-cooked." A boy crouched in the corner. He wore the same red and yellow suit, the same lightning bolt. Wally knew him at once. His son. The kid had run off three days ago, swearing he could help with the delivery. Wally had told him to stay home. The boy never listened. "You're supposed to be back at base," Wally said. His voice cracked. Wally West jr held up a small white fan. Its curved frame gleamed in the dark. "Good thing I'm not." He thumbed the power button. The blades spun and threw cool air across his father's face. "Found it in here. Been charging off the sun all day." Wally closed his eyes and let the breeze work. His skin stopped burning. The pounding in his skull eased. He felt his pulse slow from a hammer to a drum. The boy angled the fan at Wally's neck, then his chest, cooling the vial too. "Keep it on me," Wally said. "Just a minute more." The boy obeyed. For once. The two of them sat in the shade while the fan hummed. Outside, the sky had gone the color of rust. The storm wall rose on the horizon, taller than before. Wally stood. His legs held. The dizziness was gone. He could run again. "Thanks," he said. He reached for the vial. His hand stopped. The strap hung loose. The glass had cracked when he fell through the door. A thin line of cure had leaked into the dust, already drunk by the dry ground. Half the dose was gone. The boy stared at the broken vial. "Dad. Is that enough to save them?" Wally didn't answer. He didn't know. And the storm was coming.

The sandstorm hit the shelter's edge. Wally stepped through the doorway and the wind slapped him. Sand filled the air like brown fog. He squinted down the flat ground toward the settlement. He saw nothing. No landmarks. No path. The route he had planned was gone behind a wall of grit. He pulled the cracked vial close to his chest. Running blind meant running into rocks. Running into rocks meant another fall. Another fall meant the last half of the cure spilled into the dirt. He could not risk it. But standing still let the storm bury them both. "Dad, we have to move." Wally West jr crowded behind him, one hand gripping his father's belt. The boy still held the little fan. Its curved white frame hummed against the wind. "I can see shapes. Low ones. Over there." Wally looked where his son pointed. He saw only churning sand. The kid had sharper eyes, or more faith. Three days ago Wally had told him to stay home. The boy had followed anyway. Now his stubbornness might be the only thing moving them forward. "You can't see shapes in that," Wally said. "I can." Wally West jr lifted the fan and turned it outward. The blades spun hard. The small gust pushed a clear pocket in the sand, just wide enough to see one step ahead. "It clears the air. Watch." The boy was right. The fan's breeze carved a hole in the dust. Beyond it, Wally made out the low shapes. Boulders. A line of them, spaced apart. A safe lane between. "Keep it pointed forward," Wally said. "Don't lower it." They ran. Wally kept one hand on the vial and one on his son's shoulder. The boy held the fan ahead like a lantern. Each burst of air opened a new patch of ground. They slipped between the first boulder and the second. The storm howled but they stayed clear of the rocks. Then the fan sputtered. The blades slowed. The hum dropped to a whine. The clear pocket shrank and the sand rushed back in. "It's dying," the boy shouted. "The sun charge is running out." Wally pulled them both behind the nearest boulder. He pressed his back to the stone and dragged his son against him. The wind screamed past the edges. In the shelter of the rock, Wally checked the vial. Still whole. Half a dose, still safe. The fan clicked off. Dead. They had crossed the first stretch. They were past the worst rocks. But now they crouched behind a boulder with no way to see ahead, the storm thick around them, and the only tool that cleared the air gone silent in the boy's hands. "We made it this far," Wally said. He gripped his son's arm. "Now we find out how to cross the rest."

The sand climbed the boulder. Wally felt it pour against his boots and bury his ankles. The storm had stalled over them, dumping grit in one place. He kicked his feet free, but more sand slid in. In minutes the pile reached his knees. He grabbed his son's arm and pulled. The boy's legs were half-sunk too. "We can't dig out," Wally said. "It fills faster than we clear it." Wally West jr stared at the dead fan in his hands. His red mask was caked with dust. "The battery's gone," the boy said. "But the blades still turn. I felt them when I shook it." He gripped the handle and spun the center by hand. The blades moved. A thin puff of air stirred the sand near his wrist. "That won't clear a path," Wally said. "It's too weak." "Not to see with." The boy's green eyes fixed on the sand creeping up the stone. "To breathe with. If we go under, we need air." He pressed the fan to the boulder's base and cranked the blades. A small pocket opened in the sand, just big enough for a face. Wally understood. They could not outrun the pile. But the storm stalled only here. If they crawled low along the boulder's edge, out from under the worst of it, they might reach open ground. He pulled his son down. Sand poured over their backs. The boy kept spinning the fan, carving a breath of space ahead, inch by inch. They crawled. Wally held the cracked vial against his chest with one arm and dragged with the other. His son cranked the fan and pushed through the gap it made. Twice the sand collapsed on them. Twice the boy's little pocket of air kept them from choking. Wally clawed forward toward the edge of the pile. Then his hand hit loose, shifting sand instead of packed weight. Light leaked through the grit above. They had reached the storm's edge. Wally burst up and hauled his son after him. They lay flat on open ground. The wind still blew, but it moved here, carrying the sand away instead of stacking it. Wally rolled over and checked the vial. A new crack ran along the glass. A bead of liquid clung to the rim, ready to fall. He cupped his hand under it and held his breath. The drop stayed. Half a dose, minus whatever he lost before. "We're out," the boy gasped. He still clutched the fan. The blades had stopped turning. His knuckles were raw from spinning them. Wally looked ahead. The ground ran flat and open, but he saw no boulders now to mark the path. The lane they had followed was buried behind them. They were free of the storm's trap, past the rocks. But the vial was leaking, and he no longer knew which way led to the settlement.

Wally knelt on the open ground with the leaking vial cupped in his hand. The storm roared behind them. Ahead, the flat land offered no path, no marker, nothing to follow. His son dropped beside him, still gripping the dead fan. The bead of cure trembled on the cracked rim. If it fell, the settlement died. "We can't guess," Wally said. "We pick wrong, and we walk until we drop." Then the sand shifted near his boot. A line of dirt rose and crawled toward them, straight and deliberate. Wally jerked back and pulled his son close. The line stopped. A tiny shape stood on the sand, no bigger than a thumb. It grew. In one breath a man stood before them, red armor caked with grit, two thin antennae bent on his helmet. His white eyes glowed through the dust. "You're carrying the cure," the man said. He pointed at the vial, not at them. "I've been tracking the carriers for two days. You're the only one who made it this far." "Who are you?" Wally asked. "Scott Lang. The settlement sent me out to find whoever still had the dose." He crouched and studied the crack. His voice sharpened. "That won't last. One more jolt and you lose it." Wally's chest tightened. "We don't even know the way." "I do." Scott held out an armored palm. "But you won't make the walk carrying that open. Let me take it. I'll go small. I move faster close to the ground, and the sand won't crack what it can't reach." Wally stared at the stranger's hand. Two days of clawing through heat and storm, and now a man he'd met one minute ago wanted the vial. His son looked up at him, waiting. "Dad," the boy said. "He found us. Nobody else did." Wally looked at the trembling drop. His hand shook from exhaustion. One stumble on the flat would spill it. Scott's small frame would never jolt it. He pressed his lips together and tipped the vial into Scott's cupped glove. "Half a dose," Wally said. "That's all that's left. Don't lose a drop." Scott sealed the vial against his chestplate. "Follow my trail. I'll clear a line through the dust for your feet." He shrank. The man became a red speck, and a thin groove opened in the sand ahead, running toward a low ridge Wally hadn't seen. They walked. The groove led them over the ridge, and there sat a cluster of huts, roofs sagging under heat. A crowd gathered at the nearest door. Scott grew back to full size on the step and raised the vial high. "The cure is here," he called. Wally reached the door and stopped. He'd delivered it. But Scott turned to him, face grim. "Half a dose," Scott said. "We've got forty people inside. Someone has to choose who gets it."

Wally stood in the hut's doorway with forty faces turned toward him. The air inside baked thick and still. Scott held up the vial, half full, the crack sealed under his thumb. A sick woman coughed on a mat. A child pressed against his mother's side. Every one of them watched the drop of cure as if it were water in a drought. "We pick one," Scott said low, "and the rest wait for the next carrier. There is no next carrier." His glowing white eyes stayed level. He had crossed the storm to bring this. Now he handed Wally the weight of it. "You carried it the farthest. You choose." Wally looked at the vial, then at the room. He couldn't tell who was closest to death. The woman on the mat breathed hard. An old man leaned on a post, gray and shaking. Pick one, and he killed the rest. His hands curled into fists. "No," he said. "I won't name one person and bury the others." His son tugged his sleeve. The boy held up the little fan, its blades still crusted with sand. "Dad. The fan." Wally stared at him. "We spread the cure thin," the boy said. "Not drink it. Breathe it. You said one drop cracked out and spread in the dust. What if it spreads in the air?" Scott's head snapped around. "A mist," he said. He crouched and studied the fan's rounded frame. "The dose is too small to drink and split. But as a vapor, shared air, maybe it reaches every lung in this room." He looked at Wally. "It's a guess. If we're wrong, we lose it all." Wally's chest tightened. One guess for forty lives, or one life chosen for certain. He looked at his son's steady face. The boy had carved them out of the sand twice with those same blades. "Do it," Wally said. They sealed the hut's door with a blanket. Scott tipped the half dose into a shallow bowl. He shrank small and dragged a thread of cloth across the surface, wicking the liquid thin. Wally set the fan behind the bowl and spun the blades by hand. Slow at first. The cure lifted off the cloth in a fine gray haze. The breeze pushed it across the room, over the mats, over the coughing woman and the old man and the child. "Breathe," Wally told them. "Deep. All of you." He kept turning the blades. His arm burned. The haze drifted into forty pairs of lungs. The sick woman pulled in a long breath and held it. Nobody spoke. The only sound was the fan's soft whir and the rasp of breathing. They waited. An hour passed in the heat. Wally's son sat cross-legged, watching the woman on the mat. Her breathing changed first. The hard rattle softened. She opened her eyes. The old man straightened against his post and wiped his face. Across the room, the child sat up and asked for water in a clear voice. Scott grew back to full size. He pressed a hand to the woman's forehead, then checked the old man's pulse. His shoulders dropped. "Fever's breaking," he said. "All of them." He turned to Wally, and for the first time the hard set of his face cracked into something near a smile. "You didn't choose one. You saved them all." Wally sank to the floor beside his son. His arm shook from turning the blades. The boy leaned into him, grinning under his mask. Outside, the sandstorm had passed, and thin light came through the gaps in the walls. Wally looked at the room full of people sitting up, talking, alive. He had carried the vial through heat and burial and loss, and in the end a boy's idea and a small fan had stretched half a dose into enough. He pulled his son close and held him in the quiet, and for the first time in days, there was nowhere left to run.