Thar Shaddin

I'm trying to start off a plot which will feature Zebren in one district and Xyon in another. How am I best going about it?

I don't really understand what you're asking...

Maybe in "Pal Tahrenor"? Or just pick one, and specify where they are. (o_O) Unless I don't know what you're talking about, either.

Basically, the structure of TS leaves me a little confused when it comes to a plot which will have scenes in say, two districts.

Xyon, at present, is in the industrial district, and Zebren would start in the downtown and business district.

So where do I put the actual thread? Industrial or D&B?

It doesn't really matter. you could do one in both, or include both in one.

Unless you can get two teams working against each other, I think you should have the thread in the section where the final confrontation will take place and keep all of the posts constrained to that thread. This will clear up any ambiguities about what each character is doing relative to the other (in a time sense). With a small number of RPers active on the quest, having two separate threads not only runs the risk of making the quest seem lacking in substance but also makes it more difficult to follow.

I think it partially depends on how long you plan to run the story before the final confrontation. If it's going to be several days (which can amount to many, many months of out-of-game-time) then I'd go ahead and start two separate threads. While I agree that keeping it in one thread can help to clarify time issues, I personally find it confusing when a single thread jumps all over the place. It's hard to keep track of things when Xyon's conversation with X (happening in one location) is constantly broken up by Zebren's conversation with Y (happening somewhere else entirely). But that's just my opinion.

I think we'll go with two thread then.

It seems simpler to me at the moment.