Anybody who has played the Half-Life and Portal games probably knows that they are both in the same universe and that Aperature Labs and Black Mesa are rival research labs. Black Mesa is where the first Half-Life took place, and Aperature Labs is where both Portal 1 and Portal 2 took place. However, a lot of people don't know about the infamous character Doug Rattmann, more commonly known as "Ratman," from the Portal franchise. For those of you who don't know this character, I’ll be happy to fill you in.
Doug Rattmann is a former employee at the Aperature Science Labs and one of the few survivors — if not the only survivor — of GLaDOS unleashing neurotoxin into the ventilation system of Aperature Labs. With Doug being a schizophrenic, GLaDOS began to play mind games with him and tried to convince him that everything he was experiencing was a lie, part of his twisted, broken mind. Doug was able to avoid her by setting up several dens around the labs and also began taking medication for his schizophrenia — but that proved to have an even more negative effect on his mind. Combine that with being entrapped in an abandoned facility with a murderous AI, and you get quite the insane, mad man.
Now that you are up to date on Doug Rattmann and his origins, allow me tell you more about this fascinating Half-Life Easter Egg. In total, there are seven Ratman dens in Portal 2, and each of the dens was a really interesting look into the insane mind of Ratman — and even a little creepy, to be honest. However, the seventh and final Ratman den is the one I want to bring everyone's attention to.
When you enter the final Ratman den, there are cans of food in a line-up that lead to a secret room covered in drawings and more insane nonsense that you’ve seen in all the other dens. However, there is more to this den than meets the eye. On one of the walls, there is a huge painting of Chell, the silent player character, and when you approach this wall, you can hear something very strange. It almost sounds like another human voice, except it sounds sped up and is full of gibberish. Researching further into this subject, I eventually found the actual audio clip of voice behind the wall. Take a listen to this:
Now, Valve has neither confirmed nor denied that the voice behind that wall is actually Doug Rattmann (or even a voice at all) but this can't only be a coincidence. If this is Doug Rattmann, he says that he was taken to Black Mesa, who, again, is a rival of Aperature and where the first Half-Life took place. He also said that Black Mesa is where it all started and that he needs Chell and another person named Johnson.
Who is Johnson, you ask? Well, none other than Cave Johnson, the founder of Aperature Labs who died of a mysterious poisoning back in the '80s. Now, there is nothing in the lore about a Harvey character, but there is just no way that Valve put this huge Easter Egg here without a silver lining. Valve could be planning a collaboration with Half-Life 3 and Portal 3 — maybe that’s why it’s taking so long for Valve to release Half-Life 3 and why there have been no plans for Portal 3.
Maybe they’re coming out with a game where Gordon Freeman and Chell have to work together...or maybe even go up against each other! (After all, they technically are still from rival research laboratories.) Half-Life 3 could start with Gordon Freeman and Alyx a few years after the events of Episode 2, where they can meet up with Chell right after she escapes Aperature Labs.
Now, I don’t really see a lot of interesting dialogue between these two (because I think both of them were born without vocal cords), but it would still be cool to see a game that finally mixes both of these games. I mean, come on, there has to be a reason that these games take place in the same universe. Valve has never been the company to disappoint its fans and loyal customers — whatever the company does, I’m sure fans will probably respect it for the approach. Besides, all of this is really just speculation and nothing has been proven... yet.