Combine Overworld

"Somewhere in that sequence, they would have had to establish a connection with the far side. What you have there young lady, is the specific contact code for the Combine Overworld."

- Arne Magnusson

The Combine Overworld is the Combine's place of residence before invading Earth. It is possible that it was their homeworld, or another world which they have occupied.

Overview
Very little is known about this world, as it has never been directly mentioned in any of the Half-Life games, except for a vague outburst by Arne Magnusson in the Episode Two chapter To The White Forest.

Through the portal seen at the end of Half-Life 2, an orange skyline of what appears to be many Citadels can be seen. This is probably the Combine Overworld. The two Combine Gunships attacking Gordon come from that location, hinting Synths are also built there.

The Combine Overworld's climate seems to be different from that of Earth. The Advisor for instance has a small black cup over its snout, suggesting it cannot breathe Earth's air. All Overwatch forces have completely airtight outfits, suggesting that, as being human they do not need it on Earth, it could be useful in other locations such as worlds with a different atmosphere (although the outfits do not feature oxygen tanks). The Overwatch Voice also tells several times to Overwatch troops that "mission failure will result in permanent off-world assignment", hinting any Overwatch unit is to be able to operate in other Combine-controlled world, the Overworld itself or other unknown Combine colonies. This suggests that the Combine Overworld does not support oxygen or nitrogen, the primary gases of Earth's atmosphere. When Breen escaping through the portal at the end of Half-Life 2 mentions that he cannot survive in the environment beyond the portal, an Advisor (presumably) answers he could do so with a new 'host body', which Breen hesitantly accepts.

Behind the scenes
In the original final showdown conversation at Breen's office, Breen was to mention the "Aleph universe" as the universe Eli and Alyx were to be sent; this might be referring to the Combine Overworld. Interestingly, "Aleph" is the name of the main protagonist of Prospero, Valve's first game project, that the team probably recycled for it. "Aleph" is also the name of the first letter in the Hebrew alphabet, which makes sense as the homeworld is the "first" world.

Trivia

 * The Citadels seen through the portal are very similar to an early version of the City 17 Citadel used in cut propaganda posters.


 * As the retail Overwatch forces, several cut Combine enemies such as the Combine Assassin, the Alien Assassin and the Combine Guard use breathing masks, hinting they cannot breathe Earth's air, although this might be related to the old Half-Life 2 storyline when Earth's air was being replaced with toxic gas by the Air Exchange.

List of appearances

 * Half-Life 2
 * Half-Life 2: Episode Two