The default for activating the compass is c+alt. These directions are based on the compass that you can activate in your HUD. *Important*: Throughout the walkthrough I give directions like 'Follow a heading of 180'.
Ch 5: The plot unfolds on 'The Operations Level'!.Ch 4: Dang man, there's some freaky shit goin' down in Hydroponics!.Ch 3: Operation Restore Power to the Elevator.