General assumptions: You must use all nine disguises available in the eighteenth game mission.
Blackwater bodyguard disguise can be obtained in the Penthouse stage. Attack any of "standard" bodyguard, for example the opponent patrolling outer balconies. But remember that you must attack a man.
Blackwater custodian disguise can be obtained in the Blackwater Park stage. It would be best to get rid of one of persons in the guardhouse at the back of the main building.
Plumber disguise can be obtained in the Blackwater Park stage and only in one place. You must eliminate a person on the parking lot, near the side entrance to the main building.
Samurai costume is a hidden disguise. You can obtain it in the Penthouse stage, by interacting with one of many shogun armors.
Blackwater receptionist disguise can be obtained in the Blackwater Park stage. You can attack the receptionist in the lobby of the main building or look around for ready-to-wear clothes in one of side storages.
Blackwater manager disguise can be obtained in the Blackwater Park stage and in order to do it, you have to attack a proper person wandering in the main building (try to do it in some secluded place).
Blackwater Park interior park can be obtained in the Blackwater Park stage. It would be best to eliminate one of single guard, for example the one on the back of the security room.
Blackwater Park exterior park can be obtained in the Blackwater Park stage. The easiest way to get it is to neutralize one of guards standing next to the parked car near the starting point.
Blackwater tactical team disguise can be obtained only in the Penthouse stage. You have to attack one of heavy troopers accompanying Layla, and the best moment to do this is when she stops at some place and sends her bodyguards away.
General assumptions: You must find two evidences.
First evidence can be obtained in the Blackwater Park stage. The secret is located in the guardhouse adjacent to the partially flooded underground parking lot and the easiest way to collect it is when using plumber or custodian disguise.
First evidence can be obtained in the Penthouse stage. The item you're looking for is lying on the couch in the large room with the whale skeleton.
General assumptions: You can't be spotted. In order to complete this challenge in 100% you have to do this in both stages of the eighteenth mission. As always a key to success is using best disguises. In the Blackwater Park the best costume is plumber disguise and in the Penthouse - Blackwater tactical team disguise.
General assumptions: You can't use disguises. In order to complete this challenge in 100% you have to do this in both stages of the eighteenth mission. This is very difficult challenge, because in both stages you'll encounter many enemies, even on lower difficulty settings. So I recommend setting Normal difficulty level and aggressive style of play, combined with frequent healing yourself.
General assumptions: Find the movie reel and put it in the projector.
This is a two-part challenge and both parts can be completed in the Blackwater Park stage. The first step is to get the movie reel - it is located in the corridor at the back of the security room (screen above).
The second part of the challenge is putting the reel to the projector. The device is located in one of adjacent rooms.
General assumptions: Hide three bodies in the laundry chute.
You can complete this challenge in the Blackwater Park stage, after getting to the laundry shown on the above screen.
It would be best to use a radio or throwable objects to lure enemies to come to this room. After that stun or kill them and hide their bodies in the laundry chute.