Tunnels 04, Closer

Cypress trees, their lower trunks disproportionately large as if they were swollen. And everything up to a height of around four meters was stained with mud and draped with dried-out weed.
    "Flood basin," Dr. Burrows proposed, as they broke off to gaze around.
    "What's that over there?" Elliott said, pointing ahead to an area of disturbed water, its undulating surface bright green with algae.
    "A swamp?" Will suggested.
    "Let's find out," Dr. Burrows said, heading straight toward it.
    They waded through the water, which came up to their thighs, keeping an eye out for snakes or crocodiles. However, the place seemed to be populated entirely by lizards, ranging in size from small geckos to one-meter-long iguanas, but nothing more threatening than that. The lizards' iridescent skins shone vivid blues, reds and greens as they basked in the sunlight. Hardly moving, they opened their mouths to make hissing sounds when Will or any of the others came too close, or to shoot out their long tongues at passing dragonflies. Bartleby seemed to be really quite unsettled by them, and stuck close to Elliott.
    As Dr. Burrows sloshed along, he had a dreamy look on his face. "You can very easily imagine the beginning of all life in a swamp like this." He waved his hand overhead. "You've got ultraviolet light on tap all day long from the sun, and ample water, at just the right temperature. Think... maybe this very swamp was the primordial soup -- the exact place where the first unicellular organism was born, and then evolved."
    "I would've evolved pretty damn quick if it meant I could get out of this place," Will said, swatting a mosquito on the nape of his neck.
    As they left the swamp and returned to solid ground, they found that they were in a forest of thorn-covered acacia trees. Between these was a tangle of thick undergrowth, which made the going much harder, until they finally crashed through to what appeared to be a track.
    Wide enough to drive a vehicle down, the track was unnaturally straight. Will frowned as he surveyed the short grass covering it. "This isn't man-made, is it? An old river bed?" he asked, warily looking around as Elliott caught up.
    "I'd say... neither of those," Dr. Burrows replied.
    Will still didn't like the look of it. He glanced at Elliott, but she seemed perfectly relaxed.
    "Ah," Dr. Burrows exclaimed, as he spied something further down the track, and started toward it. As Will and Elliott joined him, they could see that it was a massive pile of animal dung, which appeared to be recent from the wisps of steam rising from it. "This is evidently a main thoroughfare for the local fauna," Dr. Burrows decided. "A well-used animal trail."
    "Yes. See the marks on that trunk," Elliott pointed out, "where the bark's been scraped away?"
    Will and Dr. Burrows switched their attention from the dung to the tree trunk. A diagonal abrasion went straight through to the white wood beneath, and sap had leaked down the bark and hardened into amber drips. But Dr. Burrows was more interested in the monstrous pile of dung, to which he now returned.
    "What could have left that?" Will asked, as his father crouched down and probed it with a stick. "A very big cow? An Auroch?"
    "Not a carnivore -- I can see the stones from some kind of fruit, and cellulose... bits of undigested vegetation," Dr. Burrows replied. "We need to investigate this further."
    "What, you mean look for more giant poohs?" Will asked facetiously.
    Elliott barely managed to stifle a giggle.
    "Don't be stupid. I meant that we should search for the animal itself ," Dr. Burrows replied curtly. Standing up, he checked the bearing. "And as luck would have it, this is roughly the right direction for us," he announced. Will and Elliott smiled at each other, as Dr. Burrows deliberately avoided looking at either of them, then stalked off down the trail.
    Bartleby was the first to spot the slow-moving beast some distance up ahead. With an apprehensive meow, he came to a halt, and flattened himself to the ground. Will, Dr. Burrows and Elliott crept from the trail and hid themselves in the undergrowth.
    There was a trumpeting sound and a large gray-skinned animal moved down the trail in their direction. With its heavy limbs and lumbering walk, Will immediately assumed it was some kind of elephant. And there were more of the same kind of animal following behind it in a procession.
    Will and Dr. Burrows exchanged amazed glances.
    "Probably a family group," Dr. Burrows