After landing the helicopter and it says "Checkpoint", you will see a guard on the ledge above the double doors Moss and Emile went through. Run quickly to the ledge and press X to jump and grab onto it. Move to the correct position so that you can pull the guard off. Do so and when it happens, shoot out the light. Two guards will appear from the right. On the right of the double doors is a metal object. Crouch and run over to it. Put your back against it, then peek around the corner and one guard should be moving towards you. When he gets close, the "Grab" icon will appear. Grab him and, instead of Sam holding him, the guard's head will be by Sam's knees. His legs will appear strange and it looks like Sam is holding a ghost. Note: If the guard does not approach you, whistle until he does.