Tom Clancy's Splinter Cell Chaos Theory

When you cut the power and the guard is still alive, he will come to turn the power back on. Run past him as he comes through the doorway. He will say " Is someone there?". Run through the room. When you come back, you will find out that the lights are off and the guard is gone. He is around the corner. Take out your rifle and kill him. With most guards, when they say "Is someone there?", they stand perfectly still and you can shoot them easily.

Find a man underneath one of the poles that you can climb. Climb onto the pole and hook your legs up by pressing X. Make sure that your head is pointing towards the man. Then, climb towards him. If done correctly, the interaction box should appear with the "Break Neck hit Y" message. Sam will hang down from his knees and break the man's neck. If this does not work, you can drop behind the man and grab him. Also, when you are hanging from a pipe with your legs down, press R and you will draw your 5-7 pistol. If you want to break someone's neck from a pole and they are walking about, put your legs down and draw your pistol. Then, shoot just ahead of them. They will say something like "Is someone there" and come towards you. Put your pistol away and quickly press X. Note: You may have to press X twice. Wait for the man to walk underneath and you can break his neck.

Go to Zherkezhi's apartment and make your way to the first room on the top floor. Take out the guard and go to the long dark hallway at the top left of the room. There is a keypad lock to get in; the keypad code is "5698".

Go to the open area just before you enter the penthouse. Kill the two guards and climb the pipe at one of the ends of the area. From there, go left and jump down to the next platform. The costume should be somewhere around the corner.

Once you go down to the elevator shaft Sam will consider the Descent to Hell. There will be lasers at the bottom. Once you are down there find a ladder to get back up. Once you climb it, you will end up in a small room with lasers. The costume is somewhere in the back corner.

Before you try to find the costume, locate the wrench that is laying on the ground. Then, proceed through the level until you reach the man who is shooting from the top of the building. Once you kill him, get to where he was. Then, run across the rooftop to the vent. Exit the room you fall into. If done correctly, the icon "Bash Door" should appear in the top left corner of the room. Bash the door and the costume will be in there.