Gehn, lord of ages wrote:
Does anybody know where Gehn goes when he leaves his office on 233rd? What is out there on the rest of the Age for him to do? His Books and living quarters are all in his office... I can't think of anywhere for him to go.
He's studying the Age so as to improve his knowledge of the Art (so he can avoid making some of his mistakes the next time he writes an Age, and can put in phrases that seem to have worked well) and just out of his own curiosity. He's probably spending a lot of time doing this because Riven is somewhat unsafe for him and he's working on a new Age (234th) that he wants to write well.
He might also have machinery or controls on the exterior of the Age which he might be working with (to keep his nice office maintained).
It's been a long time since I played Riven, but from what I remember of Ghen's office, I don't recall seeing a bathroom anywhere...
If I remember my Riven, Gehn rules over the natives in Age 233 similar to how he ruled over the natives in Riven (Age 5). He is writing Age 234 as a sanctuary. However, given his character, I end to think he's really just writing another universe to escape into, leaving the rest of his worlds as he puts it "to their own wretched fate".
I do wonder, now that I think about it, when Gehn first linked to 233, I wonder how he got back to Riven? Catherine's journal is explicit about how she got back to Riven from Tay, but Gehn's doesn't really mention it. I guess he could have sent some servants first to build him a power dome for his return book before he ever linked in. Still seems risky.