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Hitman/Assassination Mode - Singleplayer Map

You must infiltrate a medditeranean mansion home to a prominent counter-terrorist leader and assassinate him. The guards will be passive until you do something to offend them, so choose wisely when to attack. You will need keycards to open certain doors, and some areas are restricted. You might be able to use a disguise to sneak in....
After killing the target you must escape, by pressing E on the gate in your spawn, or kill all the remaining guards.

To play, just start the game with casual mode and join the Terrorist Team.
Try to remember not to slash your knife as you run, as the guards may see it as being agressive and attack.
Press E to interact with objects in the world, if you can.

Don't worry if you don't succeed at first - It's meant to be difficult and offer a challenge even to skilled players
If you want some tips:
The target is on the top floor of the mansion
You need a keycard to access the top floor. It is hidden in the basement...
You can disguise as a guard to enter restricted areas.
To disguise, press E on the clothes rack on the upper (not top) floor. You have to find it though....