The Tower was magnificent, rooted beneath the swelling waves and standing proudly above the inconsistency of the water. It rose firmly and elegantly, layered with stone over metal, tall and sleek in the salty breeze.

Nicknamed "Alcatraz II" by law enforcers and government officials, and "The Boat Pokey" by inmates across the country, the Peter Briggs Federal Penitentiary was famous for one reason and one reason alone: the Tower. The Tower was conceived over a table covered with cigarette butts and half-drunk cups of coffee at 3:32 in the morning. It had been an election year. Peter Briggs had won the election.

The regular prison, Maingate, framed the end of a peninsula by San Francisco that jutted into the Pacific. It contained the expendable criminal element, those with life sentences doubled back over life sentences. Yet the worst of the worst had a special distinction even within Maingate.

The Tower was fifty yards offshore at low tide. Only about eighteen feet in diameter, it housed twelve levels of prison units, two cells on each floor. It sat within an inlet cut into the craggy walls of the peninsula. When the tide rose, it inched up the side of the structure until only the last two levels peeped out above the water.

A peripheral fence blocked the prison from the vast expanse of sea beyond, its enormous posts grounded with concrete plugs in the ocean floor. Access to the Tower could be gained only by boat, and only from the heavily guarded grounds of Maingate. The guards shuttled back and forth on speedboats like little insects busy at work.

The Tower was constructed to be the most airtight security facility in the world. Like anything built with such exuberance, it had a few design flaws -- a few places where overzealousness lapsed into an arrogant carelessness. However, for the most part, the Tower was what it was designed to be: a steel trap.

Level One was used for storage only, so the second level was the lowest floor that housed prisoners. Because it was the darkest, Level Two was referred to as "the Dungeon." The loudest prisoners were kept there so their noise wouldn't disturb the guards.

The first eight levels were always underwater, and the only natural light they received filtered through the steel bars from the floors above. The twelfth level remained empty, for security reasons. Despite the tremendous precautions, the warden felt Level Twelve was just too close to freedom and the guards above.

A large fan, protected by a steel gate, was situated underneath the first level. Piping ran beneath the ocean floor from the mainland, drawing air to feed the fan. But the sluggish movement of the blades was not enough to sweep the musk from the air. Only the top four levels had vents, though those on Level Nine were never opened, as they were almost always beneath the ocean's surface.

A single carbon gaslight was encased in bulletproof glass on every other level, slightly illuminating the metal walls. These bleak lights trailed through the dimness of the Tower, making it seem as thickly claustrophobic as a mine shaft. At night, they were turned off.

The interior of the Tower was constructed of thick steel bars. There was barely a quarter of an inch between the bars and the outer wall, which sat over the steel intestines like a stone hide. Not only were the unit walls made from such bars, but also the floors and ceilings.

Home to men who could kill with paper clips and keys, the Tower was designed as the barest possible livable environment. No plaster could be risked for walls, no wood for floors. The steel bars that composed the inside of the Tower had another advantage: They allowed the guards to see through the levels to check on the inmates. Initially, the architects had experimented with an unbreakable glass, but they had found that it fogged heavily with mist from the ocean and created a ventilation nightmare.

The outside wall of each curved cell measured twenty feet, and the cells were five feet in width. Each faced its mirror image across "the Hole," an open cylinder of air that ran straight down the center of the Tower. There were spacings of eight and one-third feet between the units on each side; this ensured that the prisoners never established bodily contact, and that the guards could always remain out of reach.

Due to the fact that the ceiling of each cell also served as the floor for the one above it, the prisoners could most easily communicate with the men directly above or below them. Although this design element may have seemed a lapse in the Tower's tight security, few of the men were tall enough to reach their ceilings, even from their beds. Those who were could hardly get their fingers to the bars, let alone through them. The neck-strained interaction between the floors served the Tower's design: to break the spirits of nearly indomitable men by removing from them all the trappings of civilization.

The cells each had a minuscule toilet with a small tap that swung into place above it, allowing it to double as a sink. The toilets caught the water before it spiraled down through the barred floors. Each unit had a single mattress on a steel frame, and a thick blanket for the chilly nights off the California coast.

The Hole formed the shaft for the platform elevator, four feet in diameter, which was operated by a handheld unit. Precisely framing the elevator was a two-foot platform between the Hole and the unit doors. When not in use, the elevator was raised out of the top of the Hole ten feet in the air, leaving only the dark emptiness below.

When the prisoners were unruly or when it rained (which rarely happened), the large Hatch was swung into place underneath the raised elevator, blocking out all natural light and moisture. However, when the sun was directly overhead and the Hatch was open, light shone through the metal mesh of the raised elevator, and the two men on Level Eleven could see clearly down into the units ten levels beneath them.

A prisoner was shackled around his biceps and wrists when transported, and his thighs were strapped together to allow only minimal leg movement. He was sent down the elevator with a guard on each side. He was always gagged, and often hooded. At all times, one of the two guards had a gun with the safety off trained on the prisoner. The necessity of such seemingly paranoid precautions had been learned at painful expense. Prisoners were only moved once, and they were only moved in.

Before a prisoner was taken to the Tower, a small sensor was surgically embedded in the tip of the ring finger on his left hand. If he escaped, this device allowed his movements to be tracked. The prisoners were put under general anesthesia while the sensors were installed, and were kept heavily drugged until a significant amount of healing had taken place, sometimes five or six days. The Maingate physicians feared if the prisoners fully awakened before then, they would dig the sensors out with their nails and teeth.

Food was delivered to the prisoners twice a day. It came in the form of a large loaf containing all the necessary nutrients to allow an animal to function. A cross between quiche and bread, the loaves were light brown when cooked correctly. They required no plates or silverware, part of the reason for their continued use. They were delivered by a guard at precisely 10:30 A.M. and 7:15 P.M.; he slid them through a small rectangular slot, barely the size of the loaf itself, at the bottom of each unit door.

A long metal arm with two outgrowths at the end was used to guide the loaves through the slot. The loaves were referred to by the inmates as "shithouse bricks." They had minimal taste.

When a prisoner behaved perfectly for a week, he was allowed a large sheet of paper and two crayons with which to entertain himself. A guard held a box through the bars with a metal arm to retrieve the crayons when the time was up. This was called "Sketch Duty."

Sketch Duty was perhaps the only activity that the prisoners unanimously held to be important. It was the sole end of the prisoners' lives to obtain this hour of distraction each week. They could keep the pictures in their cells for two days, and then they were removed and taken to be analyzed at the criminal psychology department of the Ressler Institute on the mainland. The pictures were often used in lectures.

Aside from the occasional books they were allowed, Sketch Duty was all that the prisoners had to break the monotony. Inside the Tower, minutes could stretch to hours, hours to lifetimes.

Despair prevailed in the bowels of the prison; nobody would ever be released and nobody had ever escaped its dark confines. The inmates sat pressed against the metal bars of their cramped cells, reciting their tales in the broken tongues of idiots.