Free The Fall (Book 3): War of the Living by Joshua Guess

Kell tilted his gun at a steeper angle, aiming for the top of the wall.
    They were no longer firing at full speed. Now the shots came in bursts, though no order had been given. The snipers fired occasional shots, picking off the odd soul brave enough to poke his head over the wall. Kell himself fired a round every five or ten seconds, trying to make his ammunition last. Dodger had given him two extra magazines, and he was nearly through his second.
    “Come on, come on,” he muttered to the runners, who were almost at the base of the wall.
    In smooth, practiced motions, the runners slowed just enough to shrug off their packs. Kell watched in fascination, forgetting to shoot, as the one nearest him yanked the zipper open and whipped her pack in a high arc without missing a beat. Once the package was away, she spun on her heel and sprinted back to the tree line.
    Whatever was in the packs, it clearly wasn't explosives as Kell had half-expected. Five, ten, thirty seconds passed with no deafening booms or plumes of smoke and fire. It was only due to his intense curiosity that he managed an idea of what had happened. A thin curl of what might have been smoke wafted upward, there and gone in a flash. It wasn't smoke, though. Not the kind made by fire. It was a sickly pea green.
    Gas. They had thrown ampules of gas.
    Not enough to kill or probably even damage a large number of Hunters, but the intent was starting to become clear. Kell's people were doing everything they could to keep the enemy from climbing the walls, driving them into the center as much as possible.
    “Cover the truck!” Troy ordered.
    Kell was twenty feet from the access road, and felt the rumble through the ground. He glanced at the vehicle as it passed by, and in one terrible moment he knew what was about to happen.
    Kell raised his weapon, firing randomly at the top of the wall, though at this point it seemed unlikely anyone was going to appear. He was less worried about enemies raining bullets down on them—impossible at the moment—than he was for something larger and worse. Grenades lobbed over the wall might be a problem, but the smallest that came to mind. Worse would be larger explosives or chemical weapons. Whatever else the Hunters might be, they were dangerous and prepared.
    Though it felt like eternity, the assault had only begun a few minutes before. The window of surprise and disorientation was rapidly closing. If a counterattack was coming, it would be soon.
    In the corner of his vision, the truck gained speed, lumbering up the access road. It was heavily armored, especially along the front and top. No stray bullets from the Hunters would kill the driver. A smaller vehicle chased behind it, also armored.
    The opposite corner of his vision caught movement in the sky. Kell jerked back automatically, his mind immediately going to his thought about grenades, but it was a false alarm. Several brave volunteers had partially ascended the hill to lob small objects onto and over the wall. More of whatever liquid they had thrown before? Grenades?
    There were no explosions, no more wisps rising. There were, however, screams. Whatever was being thrown scared the hell out of the people behind the walls. Even as he watched, the throwers moved, some running for new bags of missiles, others continuing their efforts on a new section of wall.
    This went on for another minute, which was when the truck and its chase care reached the front gate. Somewhere deeper in the woods, a horn blared, cutting across the field like a knife.
    “Cease fire!” Troy shouted. All along the hillside, people ran back to the woods. “Pull back!”
    Kell took one last look at the idling truck, with its massive twin tanks. As he stood, he saw its door open and the driver drop to the road. The man stooped, fiddling with something on the bottom of the truck, and raced for the chase car.
    “Run!” Troy screamed.
    Kell ran.
     
     
    From where Kell had stood to the nearest wall of the