A lone patrols the lonesome street. The night air is cold and clear, a perfect night sky hangs above. The guard keeps a steady hand on the handle of his blade. His boots are clumsy and loud against the cobblestone street.
A shadow crouches on top of a vent above the sidewalk. The shadow watches, tracks the guard's movements through the spyglass in his mask. It takes the guard exactly 40 seconds to travel around the perimeter of the street. The guard travels under the vent the assassin is crouched on, walks along the sidewalk behind the shrubbery, past a guard post and stops in front of the Wall of Light before repeating the cycle over again.
The man with the mask readies his crossbow, prepped with a bolt. His steady hand aims at the guard's head, his finger on the trigger.
"Are you a killer, Corvo?" a voice inside of his own mind asks him.
"No," Corvo answers, not out loud but to himself. His finger falls away from the trigger and he straps the crossbow back on his back, waiting for the guard to pass him again.
When the guard passed his perch, the mark of the Outsider glowed on the back of his hand. In a blink of bright blue Corvo was standing silently behind the clueless man. His steps were silenced by his incredible speed. In seconds, Corvo's arm was wrapped around the guard's neck. The guard flailed and fought in Corvo's grasp, but soon collapsed into the assassin's arms, limp. Corvo hoisted the body over his shoulder, aware that, if the guard was left on the ground, the rats would devour his body. A stack of crates placed neatly near the Wall of Light caught Corvo's eye. In a second flash or light, Corvo was setting the guard on top of one of the boxes, safely out of reach from the rats, and if the guard woke up he could easily jump down without harming himself.
Of course before Corvo departed, he relieved the guard of his coin pouch. He also, hopelessly, searched for a few sleep darts. He didn't find any. Not surprising to the assassin, though. Guards were not hired to subdue. Most guards were young men who turned to the City Watch when the plague swallowed up their businesses and families. Most have never touched a blade in their lives.
On the other side of the Wall of Light, a guard yelled. Corvo spun around quickly, worried that he was been discovered. A gunshot rang out into the empty night, but Corvo found himself alone and untouched by bullets. A moan, like some dying animal gargling water. Weepers. Corvo shivered at the memory of the gray skin, the black substance that leaked from their mouths and eyes, like tar.
Corvo peered out from the corner of the deadly energy field. Three Weepers were rushing, clawing, grabbing at two guards. Both guards were regular grunts of the City Watch, young men who cringed at the sight of the walking corpses. Both were only armed with swords.
Corvo had two decisions, either stop the Weepers and the guards, wasting both Mana and sleep darts. Or leave them to fight and use it as a distraction to sneak past them.
Corvo felt a twinge of guilt for thinking of abandoning the guards to deal with the gray living bodies. He heaved a heavy sigh, and prepped his crossbow with a sleep dart. He rushed over to the Wall of Light generator, removing the whale oil power source. The Wall of Light beeped, a sign that it had powered off. Corvo quickly rolled into the scuffle, dispatching the Weepers quickly with the sleep darts, three shots, all cleanly fired into the arms or legs. Before the guards could react to their new foe, Corvo Blinked quickly out of sight, on top of a low metal balcony.
For a while, Corvo watched the two guards move the bodies of the Weepers back into the alley which they must have come from, then try to find him. After a minute or two of searching behind wooden boxes and bushes, the guards gave up and continued patrolling the streets.
Swift and noiseless, Corvo sprinted across the rooftops. The muffled and distant sound of violins and piano played, sticking out through the mute night like a blemish on the face. Corvo pictured a vision of aristocrats hiding from their wives, of women abused and drained of life, of low lights and the exchange of money to the lady of the house. The Pendeltons twins, who he would dispose of in a non-lethal way. But above all he pictured Emily, scared and nothing but a pawn in a game of crooked men and politicians who care more about their mistresses than the lives of the people they are supposed to protect.