London Eye: 1 (Toxic City) by Tim Lebbon

to the night, they left that sad, surreal place and found themselves once more in familiar streets.
    They gathered in a small square where once-tended plants had grown wild, and where birds chattered as they chose their roosts for the night.
    “It's not far now,” Rosemary said. “There's a house two streets away that I sometimes use. There's food there, and bottled water, and enough rooms—”
    “Listen!” Sparky held up his hand, eyes wide, head tilted to one side. The birds had also fallen silent, equally attuned to the sound of danger. “Engines.”
    “Quickly!” Rosemary led them across the road and through a gate into the small park at the square's centre. “Hide, stay low, and whatever you do, make sure you're not seen.”
    “Choppers?” Jenna asked.
    “Almost certainly. Irregulars hardly ever use vehicles.”
    Lucy-Anne hid with Jack and Emily behind a bank of undergrowth growing around an old oak tree. She looked for the others but they had all hidden themselves away so well that even she could no longer see them. She had the crazy idea that they had never been there at all.
    “I'm afraid,” Emily said.
    The motors were drawing closer. There were several of them, and above their grumble he heard the distinctive sound of something else: a helicopter.
    “Me too.” Lucy-Anne smiled at the girl.
    “But we're here,” Jack whispered into his sister's ear. “We're in London, and Mum and Dad will be here too.”
    “Yeah,” she said, smiling. “Do you think they'll remember us?”
    Jack tried to answer, but his voice broke. “Shh,” he said instead. He glanced at Lucy-Anne and she saw tears in his eyes. “Shh.”
    The helicopter passed overhead. She saw it through the jagged branches of the oak tree, its tail light flashing red as it hovered briefly, then thundered away across the Barrens. It was too high for its downwash to be felt, but so loud that Lucy-Anne could not even hear her own breathing. She noticed that though Emily cringed into her brother, her right hand was held out from her side, the dark lens of the camera facing up.
    As the helicopter drifted away, the square was illuminated by a flood of headlamps. Lucy-Anne tried to hunker down lower, gasping as the light fingered through bushes and between tree trunks to briefly dazzle her. The engine sound did not change. She heard heavy wheels grinding on the gritty road, and another set of headlamps swung through to follow the first. The two vehicles grumbled around the square, their engine noise intensely threatening. But behind them, a heavier sound. It rumbled and shook through the ground as well as through the air, and it made leaves in the square shake where the helicopter could not.
    “What's that?” Emily asked.
    “Don't know. Big truck.” Lucy-Anne peered through the bushes, trying to make out the shape and size of the two vehicles driving around the edge of the square. They seemed quite small, but before she could get a good look, they were gone, and the massive rumble that followed them took over.
    It echoed from the buildings around the square, shook the ground, and the lights—red, yellow, and white—slashed through the undergrowth as if it was not there. It ended the shadows in that place, and its motor sounded angry and hungry.
    The vehicle turned around the edge of the square, following the two smaller trucks that had preceded it. Through branches and past heavy limbs draped with leaves, Lucy-Anne could see its shape, and it was huge. It reminded her of an oil tanker, but its heavy grey sides looked daunting, the three conical towers on its back ugly and threatening with the stubby black guns that protruded from them.The engine tone lowered for a moment and she thought it was going to slow.
    “They can't have seen us!” Emily said, almost shouting to be heard.
    Lucy-Anne delved into her pocket for the knife Sparky had let her keep, laughing out loud at how ineffective it felt.
    Then the giant vehicle lumbered on, putting