The hardest part is working out what you have to do.
Make your way to the top of the tower, and shoot the panels off the rotating thing against a hidden timer, while under enemy fire.
Is he really doing all of this for humanity's sake? Or is he using the Combine for power (given his little slip of the tongue in 'Dark Energy', where he uses the term 'The Combine' rather than 'Our Benefactors', which he stresses the citizens to use because 'The Combine' is like a derogatory term)?
