Call in. A single player mod which plays out at the same time as Gordon and Alyx flees the citadel in Ep1. You take the role of a rebel soldier on a mission to retrieve information regarding the super portal to aid in the building of Dr. Magnussons rocket.
A fun and fairly well-made mod. Brings back memories of the calssic HL2-based mods that have recently gone out of fashion, but still give you a good time. If you havent played yet, do so!