(It's a normal day at City 17. A little resistance has formed against the Combine and Overwatch forces. However, something very strange happens as the right men in the wrong place begin to show up...)

A train enters the station, and immediately drops off a large group of TF2 classes, including Scouts, Soldiers, Pyros, Demomen, Heavies, Engineers, Snipers, Medics, and Spies run out of the train and immediately begin moving around City 17. The Overwatch forces now realized, they can't possibly handle this