Tunnels 03, Freefall

indeed, it marks the end ."
    "If we're stopping here, I could brew up some tea?" Martha offered, but no one took any notice of her, least of all Dr. Burrows, who was putting on his Bergen again as if he was going somewhere.
    "I don't get it. If this is the end of the trail, where the heck is the rest of it?" Will asked. "Where did the ancient people go from here?"
    "Faith," Dr. Burrows merely replied.
    "Huh?"
    "Take physics, for example... the lower gravitational pull that we're experiencing down here is the reason that we lived to tell the tale after falling thousands of miles," Dr. Burrows said, lobbing his luminescent orb up and snatching it out of the air by the lanyard as it drifted down. The he stuck his hand through the lanyard, winding it around his wrist so it was held securely in his palm. "And if one continues to travel towards the center of any massive body -- this planet, for instance -- then it follows that the gravity will continue to decrease even further. Maybe to nothing. Maybe to a zero gravity belt."
    "Sorry, Dad, I don't underst--" Will tried to say.
    "But I'm not just talking about faith in the laws of science. I'm talking about faith in one's convictions, in one's beliefs. For far too long, I lacked faith, and faith can move mountains, faith can open your eyes to whole new lands."
    "Well, are we going to take a breather here, or not?" Martha asked again.
    Dr. Burrows was only looking at his son as he spoke. "You think I've been callous and selfish, Will, but some ideas are too big and too important to let people get in the way. I'm sorry if you think I've been a poor father to you, but one day you'll understand." As he stepped slowly towards Will, he felt inside his coat for the radio beacon and, pulling it out, waved it in front of his son's face. "You'll be able to find me, if you want to. It's up to you."
    "What do you mean?" Will said.
    Dr. Burrows continued past Will and when he was on the ledge with just the void before him, he launched himself off.
    "Dad!" Will screamed, lunging at his father in an effort to grab him, but there was no way he could have reached him. Dr. Burrows had gone.
    "No!" Chester whispered. Martha and Elliott ran over to watch Dr. Burrows spiral into the vacuum below, the luminescent orb in his hand growing dimmer until there was no sign of it at all.
    "He just killed himself," Martha muttered in disbelief. "Is he mad?"
    After the initial shock, they all simply stared down into the infinite darkness. The Will began to whistle through his teeth in that random way Dr. Burrows did when he was deep in thought.
    "Dad may be a little crazy, but he's not mad," he replied eventually, with a glance at Martha. "What he was saying about the gravity does make sense."
    "Will, are you all right?" Chester asked. He placed a hand on his friend's shoulder, concerned at the detached way he was taking Dr. Burrows' death leap. It was the reaction that Chester would have expected.
    "By rights, the gravity should be even less towards the center of the planet, shouldn't it?" Will pondered out loud.
    "So what?" Chester spluttered. "We're hardly going to put it to the test, are we?"
    Will nodded, but not in response to Chester's question, but as if he'd suddenly remembered something.
    "Martha, you never told us what this void is called? Don't the Seven Sisters all have names, like Puffing Mary or the Pore?" he asked as he slipped off his Bergen, and began to rummage through it.
    Martha shook her head. "Nathaniel and I never got round to it, and I didn't want to have anything to do with the place after he died," she said.
    Will smiled to himself. "But it should have a name. Everything has a name. Why don't we call it Smoking Jean , after my Auntie Jean, because her flat's sort of like a black hole too," he said. He took several radio beacons and a pair of larger devices, the trackers themselves, from the Bergen before putting it back on. Then he swung round to Chester, Elliott and Martha.
    "Talk to me, Will. What are you doing with those?" Chester asked, frowning.
    Will held up one of the trackers. With a pistol grip, it resembled some sort of stubby handgun, but it had a small dish at the front and a dial at the top. He switched it on and aimed it at the void where his father's signal caused the needle to vacillate and a slow ticking to come from the device. "That's my dad," he said. Then he made a quarter turn, and the needle showed a weaker signal and the ticking came more slowly. "And