Tunnels 01, Tunnels

statues in twisted postures of frozen agony, some with their features obliterated and others with limbs missing. Rusting chains wound around the contorted figures and the posts next to them. It looked like a sculpture of some long-forgotten atrocity.
    "The Prisoners' Platform. That's where they were punished."
    "Gruesome statues," Will said, unable to take his eyes off it.
    "They're not statues, they're real people. Tam said the bodies have been calcified."
    "No!" Will said, staring even more intently at the figures and wishing he had time to document the scene.
    "Shhhh," Cal warned. He grabbed Bartleby and pulled him to his chest. The cat kicked out, but Cal wouldn't let go.
    Will looked at him inquiringly.
    "Get down," Cal whispered. Ducking behind the parapet, he cupped his hand over the cat's eyes and clasped the animal even more tightly.
    As he followed suit, Will caught sight of them. At the far end of the square, as silent as ghosts, four figures appeared to float on the surface of the waterlogged ground. They wore breathing masks over their mouths, and goggles with large, circular eyepieces, making them appear like nightmarish man-insects. Will could tell from their outlines that they were Styx. They wore leather skullcaps and long coats. Not the lustrous black ones Will had seen in the Colony; these were matte, and camouflaged with streaky green and gray blocks of dark and light hues.
    With easy military efficiency, they were advancing in a line, as one controlled an immense dog straining on a leash. Vapor was blowing from the muzzle of the inconceivably large and ferocious animal -- it was unlike any dog Will had ever seen before.
    The boys cowered behind the parapet, acutely aware that they had nowhere to run if the Styx came their way. The hoarse panting and snorting of the dog was growing louder -- Will and Cal looked at each other, both thinking that at any moment the Styx would appear from around the edge of the parapet. They angled their heads, straining to catch the least sound of the Styx approaching, but there was only the hushed gurgle of running water and the unbroken patter of cavern rain.
    Will's and Cal's eyes met. All the signs were that the Styx had gone, but what should they do? Had the patrol moved on or was it lying in ambush for them? They waited and, after what seemed like an age, Will tapped his brother on the arm and pointed upward, indicating he was going to take a look.
    Cal shook his head violently, his eyes flaring with alarm behind the half-fogged glass; they pleaded with Will to stay put. But Will ignored him and raised his head a fraction over the parapet. The Styx had vanished. He gave the thumbs-up, and Cal rose slowly to see for himself. Satisfied the patrol had moved on, Cal let go of Bartleby and he sprang away, shaking himself down and then glowering resentfully at both of them.
    They skirted cautiously around the side of the square and chose a lane in the opposite direction from the one they assumed the Styx had taken. Will was feeling increasingly tired, and it was getting harder for him to catch his breath. His lungs were rattling like an asthmatic's, and a dull ache gripped his chest and rib cage. He summoned up all his energy, and they darted from shadow to shadow until the buildings ran out and the cavern wall was in front of them. They ran alongside it for several minutes until they came to a huge stone staircase cut into the rock.
    "That was too close by half," Will panted, glancing behind them.
    "You can say that again," Cal agreed, then peered at the staircase. "Is this the one?"
    "I think so." Will shrugged. At that point, he didn't much care; he just wanted to put as much distance between them and the Styx as possible.
    The base of the stairs was badly damaged by a massive pillar that had crashed down and shattered it, and at first the boys were forced to clamber up several broken sections. Once they had reached the steps, it wasn't much better; they were slick with black weed, and the boys nearly lost their footing more than once.
    They climbed higher and higher up the stairway and, forgetting for the moment how ill he felt, Will stopped to take in the view from above. Through the haze, he caught sight of a building topped with a huge dome.
    "That's the spitting image of St. Paul's Cathedral in London," he puffed, getting his breath back as he peered at the magnificent domed roof in the distance. "I'd love to have a closer look," he added.
    "You've got to be