Checkpoint A. When the level begins, jump up a floor. Run down the staircase. 
  The Mirror's Edge logo will be at the bottom. Drop down onto another vent, 
  then Wall Run across to another roof to find a bag.
  Checkpoint B. Use the pulley to fall to the ground, then enter the warehouse 
  area. Wall Run, then jump onto the vent to enter the office at the far end of 
  the red walkways. A bag is on a shelf near the exit door.
  Checkpoint C. Enter the next area to reach a second office. Go to the ground 
  level, and jump over the fence. Run to your right past the forklift to the 
  corner that is opposite from the pillar and locked door. Jump up to reach a 
  gap in the shelving with a bag.