Half-Life 2: Episode One (2006)
Half-Life 2: Episode One is an all-new episode created by Valve that continues the Half-Life 2 single player adventure. Players take on the role of Dr. Gordon Freeman, who must face the consequences of his actions in City 17 and the Citadel. Along with Alyx Vance and her robot Dog, players join forces with the resistance to battle against Combine forces. Through this thrilling adventure, players will experience a gripping story line filled with intense action and immersive environments.