In Deus Ex: Human Revolution for the PC, PS3, and Xbox 360, there is a mission where you have to sneak into the police station in Detroit to get some information.
You can’t just walk into the police station through the front door guns blazing obviously, so how do you get in?
Facing away from the police stations front doors, look out diagonally to your left a little ways for an alley and you’ll see a manhole that you can enter, which will take you to the sewers.
There are a couple thugs down here that you may need to knock out on your way.
At the other end of the sewers is a ladder leading up. Go up the ladder to reach the side of the police station. You’ll find a ladder here going up the side of the building that is just out of reach. Grab a box nearby to climb on it and reach the ladder.
If you’re a skilled hacker, there is a security panel here that will lead you almost directly to the objective. If not, you’ll have to crawl in through the air vent and make your way to the objective that way.