Or better it is set outside of it in the first 'Robotcity' the robots had created.
Not only that but Gedächtnis mentions a war that had happened years ago, a battle against humanity.
Gedächtnis also mentioned that the city is surrounded by a desert, the city that the robots had built in Animatrix was located in Saudi Arabias Rub' al Khali, which is a large desert.
I suppose this is just a shot in the dark, but come on! A famous character who develops a lifelike puppet. It can't be a coincidence, can it?
Instead of grooming Drossel to succeed her father, he keeps her confined to the mansion and occupied with an endless stream of trivial diversions, with pains taken to keep her ignorant of matters of state while he rules the robot empire himself as a Regent for Life
- The mansion is clearly something of a castle, and the presence of a surrounding city suggests that he and Drossel occupy the position of feudal lords, but exactly zero mention is made regarding the governance of the city. Given Gedachtnis' general reluctance to divulge operational information to Drossel, it's not a stretch to suppose that he is running things and just not telling her about it.
- Furthermore, the mansion is apparently a significant enough target to justify the humans attacking it not once, but twice. Near the end of Season 1, Gedachtnis states that the humans have surrounded the mansion at a distance of 50 kilometers...which would make for a 300km perimeter, which implies a rather large army. And something tells me that they're not there to stop a little girl-bot from watching archival footage of dolphins.
- While outwardly encouraging Drossel to learn more about the humans, his "lessons" are calculated to cast them as strange, unknowable, and boring, effectively squelching Drossel's curiosity lest she take an interest in matters of diplomacy and interfere with his own designs.
- Notably, the diplomatic situation seems to have deteriorated between Charming and Season 1, which suggests that Gedachtnis' foreign policy may be less than benign. Given Drossel's general good nature and stated desire to make peace with the humans, he may fear that she would...disapprove of his diplomatic methods.
- Also, the "history" he relates in Charming seems to have jack-all to do with anything: it sounds very much like a creation myth interspersed with Windstille propaganda, and has little explanation for such things as "why the humans maybe want to kill us."
- Also also, the "Human Table Manners Simulator" looks an awful lot like a spacesuit, and the human vehicle looked an awful lot like a space capsule. Given everything else, it's not a stretch to suppose that the whole "Charming" thing was a fairy tale mocked up by Gedachtnis to distract Drossel. His bemusement at Drossel erasing the alterations to the "Warning" sign was because this meant that his charade was falling apart.
- When the humans first begin shelling the mansion, he tries to gloss over the matter — and when Drossel seems confused by their sudden absence in the next episode, he brushes it off and they carry on with shenanigans. Later, it's revealed that he had to "dismiss" approximately 2,000 (of 4,000) stealth-enabled robot Ninja Maids, which has resulted in some disrepair to the castle. Gedachtnis couldn't possibly have dispatched the "mansion staff" to slaughter the attacking humans, could he?
- And when the Laugh Track occurs, he pooh-pooh's Drossel's claim that there's an intruder in the mansion...and then quietly murders the intruder once she leaves the area.
- And furthermore, "Fireball" is a pretty ominous name for a defense strategy, isn't it? It sounds like there may be a bit of Nuke 'em involved, and considering that the mansion is in the middle of a city...
- Given Drossel's period of hibernation (and memory loss) between seasons and the exceptionally long timespans alluded to in the series, this cycle may have happened multiple times before. Perhaps the scrambling effect of the hibernation is necessary to keep Drossel's mental age from progressing beyond childhood, and to reset her naivete when she begins to get suspicious of Gedachtnis' manipulations.
- Finally, this whole charade may be necessary because Gedachtnis is both compelled to obey Drossel and prohibited from harming her. Otherwise he could just kill her or imprison her overtly - but as it is, he has to keep her occupied and ignorant.
- If I remember right, he seems to be forced to obey Drossel whenever she orders him around (except when given conflicting orders, such as the "No Pets Allowed" rule)...but doesn't seem to have any problem with lying to her.
- We see that Gedachtnis is capable of countermanding Drossel's orders when they conflict with preexisting "rules" — but the most prominent such rule that we see ("No Pets") was instituted by Drossel herself. However, Gedachtnis made no attempt to explain this to her and give her an opportunity to rescind her prior directive. It's not a stretch to surmise that other "rules" may have had similar origins...such as the one which prohibits Drossel from leaving the mansion.
In Conclusion, Gedacthnis is a Treacherous Advisor
, Manipulative Bastard
, and probable Evil Overlord
who's been imprisoning Drossel in a state of childlike ignorance for thousands of years while he conducts a war of conquest against the humans outside...a war which the humans finally seem to be starting to win.