Gordon Freeman wakes from stasis to find that a lot has changed since he defeated Nihilanth and was subsequently plucked from Black Mesa by the G-Man. As Freeman comes to, he comes to know that the Earth has been taken over by a hostile alien civilization known as the Combine. He must pass through various Combine-operated security checkpoints to get to wherever he is going. However, before he can figure this out, he is detained by a security officer and taken to an interrogation room. The officer then reveals himself to be a former co-worker, and introduces Freeman to Alyx Vance once in the relative safety of Dr. Isaac Kleiner's Lab, where they've contracted a rudimentary teleporter to send themselves to the anti-Combine base resistance base known as Black Mesa East. Unfortunately, Dr. Kleiner has a pet headcrab named Lamarr, who interrupts the teleportation process, causing Freeman to teleport to a few open locations before landing just outside the lab. This alerts the Combine to his presence, and he must fight his way to Black Mesa East, not knowing what awaits him there.
Fans of the original Half Life seem to have taken to the sequel just as easily, but it has also attracted new attention from gamers. Additionally, HL2 was released as part of the Orange Box in October of 2007, which also featured 2 additional HL2 episodes, Team Fortress 2, and surprise favorite Portal, which was so successful in its own right that a sequel is now due in spring of 2011.