The soft soil underfoot had become hard bedrock before he knew it. Once out of the woods, he suddenly found himself atop a crag. With the rugged hardness of rock to reassure the soles of his feet, he made his way to the edge and peered over to find a sheer ledge dropping off no more than his own height. Here the woods abruptly ended, and below the drop extended a sloping strip of land covered by fallen leaves. Although there should have been something like a small stream winding its way down the eastern slopes of the mountain, no marsh was visible from this point onwards, nor was the sound of running water to be heard.
It felt like but a short while ago that the noonday sun, reflecting off the water, repeatedly caught the eye. Yet the stream vanished as if swallowed up by the earth.
There was little need to check the map. The underground water that welled up from this stretch of mountains fed a tributary of the River Tama, and upon swelling to much greater proportions, flowed into Tokyo Bay. Beneath the rock that felt so rugged to the soles of his feet ran the groundwater in streams formed of rainwater that had percolated through the hard rock. As Fumihiko Sugiyama thought of that crystal-clear water, something struck him as strangely incongruous. He lived in a high-rise condominium with a magnificent view of Tokyo Bay. He gazed upon the River Tama every day and could clearly remember the colour of the water. The water was quite filthy and could only be described as a dirty blackish gray. He wondered how the unsullied, crystal-clear water flowing from the source could be transformed into such an unsightly mess by the time it reached Tokyo Bay. As he stood atop the tiny crag, Sugiyama wondered how fascinating it would be to observe every subtle and detailed change in the colour of the water as it flowed from the source to Tokyo Bay.
Sugiyama was about to jump down from the low crag when he found himself faltering. It was not that great a drop and could have been jumped easily. Yet he felt a surge of unease. The ground at the bottom of the small cliff was covered with leaves, which made for a strangely uncertain footing. Fallen leaves had frequently caused him to slip in the past while traversing mountainous terrain. Wet leaves stuck to the surface of rocks were a particular hazard because a hiker could easily slip and fall. Although the layers of leaf mould that lay under the leaves posed little problem, the leaves could also conceal a hollow in the rock or a tree root, which were often the cause of sprained ankles. Sugiyama was not concerned about spraining his ankle, however. He had visions of something like a bottomless dark pit lurking beneath the leaves. As he thought of the terrible consequences of jumping into something of that nature, he stepped back from the edge. Behind him could be heard the rustling of bushes being pushed aside. Suspecting that it wouldn't take Sakakibara much more than a minute to catch up, Sugiyama decided to wait for him on top of the ledge. Sakakibara was out of breath when he arrived where Sugiyama stood. Sugiyama thrust his chin in the direction of the ledge to call Sakakibara's attention to what lay below. Sugiyama thought his expression would have sufficiently conveyed to Sakakibara his dilemma as to whether they should jump down. However, with a display of characteristic obtuseness, Sakakibara sprang off the edge without so much as checking his footing. He landed with a thud on the fallen leaves below. Due to the slight downward slope of the ground below, Sakakibara had landed on his rump. Sitting there with both arms extended behind to support himself, he pointed his jaw upwards and grinned at Sugiyama as if challenging him to stop wasting time and join him on the double. A man of hefty build and the antithesis of agility, Sakakibara was also a reckless character who had not infrequently provided Sugiyama with hair-raising moments in the past.
'Are you all right down there?' asked Sugiyama.
As if prompted by the question, Sakakibara started to rise to his feet, the sardonic smile still visible on his face. At that moment, however, his foot slipped on the leaves, dropping him down heavily again on his rump. Sugiyama laughed out loud. Preoccupied by something all of a sudden, Sakakibara crawled face up to directly under the ledge and started to investigate the surroundings with a look of grave concern on this face.
'Say, look at this!'
He raised his hand aloft and signaled to Sugiyama to hurry and jump down. Gauging the steepness of the incline below, Sugiyama jumped and landed on his feet; he had managed to keep his balance and only needed one hand on the ground to steady himself. He turned to find Sakakibara now lying on his stomach, his face close to the bottom of the ledge. Right next to Sakakibara's rotund face gaped a dark hole similar in proportion to his friend's face. Crawling up to Sakakibara, Sugiyama peered into the hole.
'Could it be the entrance to a cave?'
Sugiyama's tone suggested that he was not so much asking Sakakibara as himself. He didn't want to get his hopes up, only for them to be dashed, so he suppressed the excitement he was beginning to feel. They had hiked the mountainside for half a day now and the only openings had been fissures in the rock, cracks hardly wide enough to insert his arm, let alone his body. Thus, trying not to get his hopes up, Sugiyama found himself believing that this aperture, too, was probably nothing more than the den of some animal.