Martin Davies sat with a copy of the PG&E underground cable layout for the El Camino, a street running through the heart of silicon valley. He sipped at his coffee that had been brought by Fred Sanders. Martin had given Fred a free apartment in return for his services of cleaning and cooking, while he was not attending college.
"There is nothing about a concrete wall on this." stated Martin, thoughtfully.
"I am sure that it is a recent map. Maybe the wall is left over from some old mine." suggested Fred.
"No, I am sure that this used to be an orchard. The city records don't show any structures here, and it is too big for a well casing." mused Martin.
Martin got up from his kitchen table and began walking towards the hall. His house was a modest one by most of the country's standards. It was a single story, three bedroom house with a both a front and a back yard. The house was located in San Jose, close to where the El Camino changed into Santa Clara street. Martin continued his walk to the hall closet and flipped the hall light switch up and down in a pattern of flips similar to Morse code. The light did not flicker, but came on and remained steady, due to the short turn-off delay. A panel in the floor rose up towards the end of the hallway, uncovering a stairway. Martin went down the stairway, then closed the trap door behind him. This level contained little besides the machine shop and an elevator. In the elevator, he pressed -3 and went down three floors. Martin had been an engineer in a manufacturing plant when he had begun construction under his house. It had seemed like a good idea to make a bomb shelter and he had started to dig one. He had little problem with the physical part of the digging due to his health club membership, which he soon cancelled as the work had gone on. About half way through the digging, he developed a new method of getting rid of the dirt, while making the shoring for the walls and roof at the same time. The machine was a combination of a free energy N-machine, a high power radar like device, and a remote control tracked vehicle. The device simply melted the earth into magma. The dirt from the tunneling was mostly empty space and when melted, it would lose much of it's bulk. In some areas it was possible to melt a large enough tunnel without having to carry out any dirt at all. The bomb shelter had grown into a full machine shop with milling machines and lathes. The floor of the garage was converted into a motorized elevator for bringing in large pieces of equipment and furniture.
Many tunnels and spaces were dug while Martin was perfecting his digging machine, but he had never gotten an excavation permit. After much thought, and after his credit cards had all reached their maximum limits, he was listening to a person complain about the high rent, which is a really common thing in silicon valley, and he hit on the idea of renting out the space that he was creating. He started with only a few people. Once all of the problems were solved, such as tapping into the water and sewage lines, and ventilation by openings near storm drain gratings, it became allot easier to make just one more apartment with an opening behind a bush, or in an alley. Soon Martin was digging multi floor apartments with secret openings near bus stops and in parks all around the valley. With the average cost of rent in the valley, people were more than happy to pay many times the cost of the construction. When the select few found out that there could be a living space within walking distance of their work, or a nearby bus stop, they went nuts. No matter that they were sworn to secrecy, or that there were no windows. Just the idea of three quarters the normal cost of rent and no commute was really a blessing.
This business had made Martin very rich, and he happily puttered around in his shop, in between cruses to Alaska and trips to Europe, until he run into a wall of concrete that was not supposed to be there.
Martin left the elevator and walked past several darkened rooms where the machine controllers were busy controlling the digging machines. One control room had a sign on it, reserving the room for him. Entering the room, Martin sat down and thumbed the starter for the N-machine in his digging machine. The various displays and screens lit up and the sound of the fans could be heard. Two computer screens were mounted on the main panel and there was a shroud that slopped up toward Martin's eyes. Each monitor was updated from one of the two cameras on the remote machine. Various messages from the remote computer were also put at the bottom of the two screens and audio prompts were also given through the head-phones that he put on. The view was nearly 3D and Martin had become an expert at controlling the machine through the two joy-sticks that were mounted on the arms of the chair. Rarely would he need to touch the keyboard that was on a shelf nearby.
This digging machine was named Rover, and the other machines also had the names usually given to dogs. Rover was now staring at a gray wall that covered the face of the tunnel. The walls of the tunnel were rounded and lumpy. Usually a crew would follow up in the cooler parts of the tunnels, after the digging was done. The clean up crew would shear off the outcrops and clean up the debris. This was just an exploratory tunnel, so it was quite rough. Martin zoomed in on the cracked and pitted concrete wall. The pitting was due to the arcing and gassing of the re-bar as the micro-wave beam heated the metal into gas. The cracking was due to the shear heat and the melting of the nearby dirt.
Martin backed Rover out of this short tunnel and drove down a ramping tunnel for about a hundred yards. This hundred yards of travel down the ramping tunnel was equivalent to about a hundred fifty feet of elevation. The ramping tunnel ended at a sharp turn to the left, where he had left off digging the last time.
The boulder crew had removed the boulders created by his last dig, so Martin was able to drive up towards the face. He aimed at the hole near the top of the tunnel at the face, and turned on the cooling water before powering up the main beam. The beam was nearly invisible save for a faint bluish glow, and occasional small yellow bolts of arcing. Soon the lower part of the hole in the face began to glow red, then orange and up to white before a trickle of molten lava was seen to flow down the face to the waiting cooling water on the tunnel floor. Huge gouts of steam filled the tunnel and Rover automatically swhiched over the infra-red cameras. The noise was heard by Martin through the head-phones as hissing, crackling and the buzzing hum of the main beam. At first it would seem that sound would be a useless frill, but allot of problems could be averted due to warning sounds. The sound of a failing bearing, for instance, could be heard long before a serious problem occurred.
Martin did not drive toward the face. He instead played the beam across the face while maintaining a twenty foot distance. He allowed the main beam to run until it had melted a tunnel that was about half way to the floor of the present tunnel. This tunnel was about fifty or a hundred feet farther along then when he had started. The steam was now thicker than any white out fog bank above ground. There were pools of molten and crusting lava on the tunnel floor. Droplets of water rained down from the roof of the tunnel and the lower part of the face was eaten away by small rivers of white hot glowing magma.
Rover backed out of the new tunnel and drove up the ramping tunnel to a spot that was a hundred feet higher in elevation than where Rover was originally parked. This tunnel was nearly to the desired floor level, and had gone past the plane of the wall that had been discovered. Martin played the main beam across the floor and melted the remaining lumps into a uniform pool while backing up along the tunnel. This formed the completed floor of the tunnel. Of course Rover would be seriously damaged if it was driven over this new floor even a day after the last melting. The new floor would be left to cool for around two weeks before actual people could visit this spot. In this case the cooling would be hastened by spraying water periodically.
Martin shut down the beam and drove down the ramping tunnel to a short tunnel that was mid way between where Rover was originally parked and the tunnel with the new floor. This tunnel was nearly ready to intersect the plane of the concrete wall that had been discovered. As usual, the first melting was done at the top of the face. The beam caused the dirt to crackle and glow, then change to molten rock and flow down the face of the tunnel.
After he had been digging for around ten minutes, Martin heard a screeching noise and the buzzing tone of the main beam changed. Martin immediately shut down the main beam, having found what he was looking for. The screeching noise was caused by the vaporizing of the metal re-bar that was a part of the concrete wall, and the change in pitch of the beam was due to the temporary short circuiting of the beam by the metal before it was vaporized.
Martin drove Rover back to the original parking spot and shut down the N-machine, then shut down the power to his console. He walked back to the elevator and went back through the trap door in his hallway.
"How did it go" ? asked Fred as he placed a steaming plate of spaghetti on the table.
"It is less than seventy five feet high and more than two hundred yards long. I need to run a sonic probe in the upper tunnel as soon as it cools. That should show how wide it is." stated Martin, sticking his fork into the spaghetti.
"Yea. Maybe it is someone else's tunnel"
"Could be. It is a bit too square for a pipe line."
"How is school?"
"Ok. There sure are plenty of willing customers for you. It is too bad that most of them would be bad risks."
"Yea, but give them a few years and they will be back here. Once they get stuck into a stable job, the risk becomes lower." stated Martin.
Martin spent the next week playing around in his shop. Sometimes he would build a device just because it would be challenging and would look good as part of the changing art pieces that decorated his living room. This was interspersed with some time spent reading and watching TV. Martin had no need to work any more. He had a small army of diggers, support personnel and maintenance workers. These people were well paid out of the monthly rent from nearly three thousand tenants. Sometimes a single apartment or a small group of apartments would get discovered. The expense to destroy an apartment with it's cast rock walls of two or three feet in thickness, was just too great for anything to be done besides installing a lock on the door. There was no budget for following underground tunnels that been back filled by melted rock, so the staff was fairly safe.
When the week was over the floor of the tunnel above the discovered wall was cool enough to walk on due to the water that had been sprayed onto it three times per day. Martin accompanied the operator of the sonic probe and helped place the array of micro-phones. A thumper was brought in and the noise was monitored as the machine made rhythmic noises while it hopped up and down on it's single foot. The thumper unit was moved to other tunnels so that the sounds from the array could be made into a pattern. This pattern was displayed on the operator's lap-top computer. A square shaped tunnel was clearly seen that went beyond the range of the sonic probe in both directions. Over dinner Martin started a conversation with Fred.
"It is definitely a tunnel. The thing is a rectangle that is twenty five feet high and seventy feet wide. I have a mini camera on order and I am going to risk drilling a hole in it." stated Martin.
"The worst it could be is a pressurized natural gas main." warned Fred
"Can't be. I've got all the plans, besides most of those are round."
"Ok, well you might be interested in that package on the coffee table that came in today."
"Great, thanks Fred"
Martin called up one of his managers and told him to have a maintenance worker meet him at the wall with a rock drill, then headed for his elevator. A small hole was drilled and the pressure difference created a slow moving wind of fresh air. The worker put the small camera down the hole and connected it up to a color monitor. Clearly visible on the monitor were train tracks complete with an electric third rail.