They split up into three groups of two and a lone sergeant. They emerged from the last steps onto the system of catwalks that ran above the cellblocks and Main Street.

The first pair to find one of the riflemen patrolling the catwalks came striding up together, both looking concerned. One of them said, “We’re filling in from the day shift tonight, and we’ve got to make an extraction from a cell. They warned us he’s a badass, and he’s got a history of fighting back. Would you mind helping us out? If you’ll stand by with the rifle where he can see you, things will go a lot easier.”

“Sure,” said the catwalker. “Where is he?”

“D Block, cell eighty-nine.” The first one set off ahead, and his companion let the catwalker go next while he followed. He took a couple of steps before he had the metal baton from the dead guard’s belt extended. He swung it downward into the rifleman’s head. The impact made a hard, hollow sound, and the guard collapsed. As he started to fall, the first man pivoted and wrenched the rifle out of his hands, took the guard’s spare magazine from his belt, and set them on the catwalk. Both men hoisted the guard by the arms and draped him over the railing. Then they squatted to lift his legs and released him headfirst.

The second and third pairs of inmates found the other two catwalkers within a few minutes and let them drop to the pavement of Main Street too. Now the seven uniformed inmates had three military-grade rifles and six loaded magazines. They came together at the door to the passage to the outer wall and climbed the steps.

Three guard stations overlooked the outer yard of the prison. They were referred to as “towers,” but they were fixed concrete turrets built along the top of the wall. Each held two men with scoped rifles, mounted spotlights, and binoculars. These men were the deterrent of last resort, the certain way to control the open yard, the top of the wall, and the entrances and exits of the prison if everything else went wrong. The towers were fortified against most kinds of attack, and they contained large caches of ammunition in case of a lengthy standoff. Prison policy, ever since the mission of the prison had been revised, was for the tower guards to lock themselves into their towers for the whole shift, not opening the door for anyone until they were replaced at 7 a.m. The lights inside the guard towers were dim, like the dashboard lights of a car, to keep their vision of their targets bright.