1. Advisor sent Recon team including Clone 36 to Arbeit Facility.

2. Mossman immediately boards a chopper from Black Mesa East and flew to Arbeit Comms after saving Eli and Gordon, after arrived, did her researches and recorded everything.


It's not certain the above two events which one happens before another, timeline wise the clone might be down in the Arbeit/Aperture facility for a long time, so we can assume that the main goal of Evil 36 is to recon the Arbeit Comms rather than track down Mossman

3. Clone team failed and Mossman escaped, both factors combining causing the Advisor activated Main 36.


Between event 1 and 3, Citadel teleporter Blew up


4. Gordon was buried, while 36 go through Aperture Tests and Exhumation. Mossman arrives at Arbeit 2 to sent her research to C17 rebels.


According to the Emails of the original Half-life 2 dev team and Episode 1, Gordon was buried for one or two days before Alyx manages to find him. That gives Walker enough time to travel through all these areas and reach Arbeit 2 (As we saw at least a day-night cycle)


5. 36 failed to capture Mossman at Arbeit 2 facility, Mossman escaped and transmission was interrupted and intercepted by the Advisor, which ends up in C17 citadel's database.


6. Gordon was found by Alyx and watched the transmission, while 36 made his way to Arbeit 3 and gone after Mossman.

7. 36 entered Entropic Control, defeated its clone while Gordon and Alyx trying to escape C17


8. 36 met with Scar 0, survived Entropic Lift control to anomaly while Gordon and Alyx witnessed the Ruins of Citadel creating a Portal Storm, which spread to the Entropic Lift Control as well.


9. Alyx got injured by a Hunter while 36 fighting the Advisor, at this point, Vortigaunts has begun their Advisor hunting and come to help 36.

10. 36 meets G-man, Gordon finds Antlion Extraction, Vortigaunts started to heal Alyx, giving G-man the opportunity to abandon 36 and went talk to Gordon.


As the previous chapter stated, if the portal storm is manifested from the Citadel, that will explain why G-man will abandon 36 mid-conversation, which also connects the timeline of these two series.




The real problem is why would G-man brings Aiden to his old Hideout.

My suspect is on--Remember where G-Man brings Gordon after the HL1 event? The tram of Black Mesa, a place Gordon often visits and Familiar with

G-Man brings Shepherd to the Osprey, where as a HECU soldier, he sure spends a lot of time training on there.

The reason G-Man brings 36/Aiden Walker to his old apartment/ward, in my speculation, is because He wants to hire him , make him a Candidate, or at least, make him a backup plan and hold him in suspension. If what I speculate is true, that means G-Man has already lost control of Gordon Freeman, makes the Vortigaunt's stealing a prior event to EZ2.

Another problem is that, as 3650 woke up, the citadel is already in flames. This means Vorts must've already got Gordon Freeman out from the explosion and G-Man's suspension. Combine that with the portal storm we witnessed underground, I lean toward my opinion.

The last detail that makes the ending event happens after the Citadel's total destruction, is a minor detail/gameplay mechanic.

I don't know if a lot of people have noticed, but during the final battle with the Advisor, the unit 36 summoned using Xen Relay Grenades are no longer Xen creatures, but only Vortigaunts. A lot of Vortigaunts, all without shackle.

I believe these Vortigaunts have scrambled the Xen relays, or rather, just using the borderworld Xen as their rally platform for a jumping pad, and ended up here to help 3650 fight. It's obvious that these Vorts knew what they're doing once they've arrived, as they immediately starts attacking the Advisor and avoid attacking 36, instead of trying to kill both of 36 and Advisor or run away from the situation.

After defeating the Advisor, if 3650 talk to the Vorts, they replies with "We will continue our hunt for the Advisors."

This line basically confirms the event of the final battle after Citadel's Utter Annihilation. As Vortigaunts did not start hunting for the Advisors until they've ejected from the Citadel throughout numerous Capsule.