Tunnels 01, Tunnels

Colony."
    "It was Will's idea," Cal replied. "It sort of worked."
    "Sort of," Tam said, looking with concern at Will, who was steadying himself against the wall, the rubber of his mask scored with deep gouges and one of his eyepieces shattered and useless. "You all right, Will?"
    "I think so," he mumbled, holding his blood-soaked shoulder. He felt a little woozy and detached, but couldn't tell if this was because of his wounds or because of the overwhelming sense of relief that Tam had found them.
    "I knew you'd not be able to rest with Chester still here."
    "What's happened to him? Is he all right?" Will asked, perking up at the mention of his friend's name.
    "He's alive, at least for the time being -- I'll tell you all about it later, but now, Imago, we'd better make ourselves scarce."
    Imago's massive form slipped into sight with unexpected fleetness, his baggy mask twisting furtively this way and that, like a partially deflated balloon caught in the wind, as he scrutinized the murky shadows. He swung Will's pack over one shoulder as if it weighed nothing, and then he was off. It was all the boys could do to keep up with him. Their flight now turned into a nerve-racking game of follow the leader, with Imago's shadow piloting them through the miasma and unseen obstacles while Tam brought up the rear. But the boys were so very grateful to be back under Tam's wing that they almost forgot their predicament. They felt safe again.
    Imago cupped a light orb in his hand, allowing just enough light to spill from it so they could negotiate the difficult terrain. They jogged through a series of flooded courtyards, then left the fog behind as they entered a circular building, racing at a staggering pace along corridors lined with statues and flaking murals. They slid in the mud on the cracked marble masonry until they found themselves hurtling up stairs of black granite. Climbing higher and higher, they were suddenly out in the open again. Traversing fractured stone walkways that had long sections of their balustrades missing, Will was able to look down from giddying heights and catch views of the city below between the meshing clouds. Some of these walkways were so narrow Will feared that if he hesitated for a second he might plunge to his death in the foggy soup that masked the sheer drops on either side. He kept going, putting his trust in Imago, who didn't waver for an instant, his unwieldy form driving relentlessly ahead, leaving little eddies of fog in its wake.
    Eventually, after haring down several staircases, they entered a large room echoing with the sound of gurgling water. Imago came to a halt. He appeared to be listening for something.
    "Where's Bartleby?" Tam whispered to Cal as they waited.
    "He saved us from a stalker," Cal said despairingly, and hung his head. "He never came after us. I think he may be dead."
    Tam put his arm around Cal and hugged him. "He was a prince among animals," he said. He patted Cal on the back consolingly before moving forward to confer with Imago in hushed tones.
    "Think we should lie low for a while?"
    "No, better to make a break for it." Imago's voice was calm and unhurried. "The Division knows the boys are still here somewhere, and the whole place'll be riddled with patrols in no time at all."
    "We keep going, then," Tam concurred.
    The four of them filed out of the room and traveled along a colonnade until Imago vaulted over a low wall and slid down a slimy bank into a deep gulley. As the boys followed him, the stagnant water came up to their thighs, and thick fronds of glutinous black weed hampered their movements. They waded laboriously through, lethargic bubbles rising up and clumping together on the surface. Even though they were wearing masks, the putrid stench of long-dead vegetation caught in their throats. The gulley became an underground channel, and they were plunged into darkness, their splashes echoing around them until, after what felt like an eternity, they emerged into the open again. Imago motioned for them to stop, then scuttled up the side of the channel, squelching off into the fog.
    "This is a risky stretch," Tam warned them in a whisper. "It's open ground. Keep your wits about you and stay close."
    Before long, Imago returned and beckoned to them. They clambered out of the water and with sodden boots and pants crossed the boggy ground, the city finally behind them. They went up a slope and then seemed to reach a plateau of sorts. Will's spirits leaped as he