Q:

Who started the other fight club chapter?

In Fight Club, there's a scene where Tyler Durden and the Narrator are discussing new fight club chapters, and there's one where they both deny starting it, and claim to have thought the other started it. I see three main interpretations of this scene:

The straight forward one: some other member of Fight Club started another chapter.
Tyler Durden started the chapter, but was messing with the Narrator's head.
There's actually a third personality that neither Tyler nor the Narrator is aware of.

Which is most likely the answer, based on actions by Tyler and the Narrator in the movie?  If anyone can also cite book sources, I'll take that too.

A:

It seems pretty clear that it was Tyler. It's possible that some of these chapters were self-starting but Tyler often kept the Narrator in the dark, even lying to him whenever he wants... but the the script has the Narrator (called "Jack" in the script) say..

Every city I went to...
...as soon as I set foot off the plane..
...I knew fight club was close.
Tyler was setting up franchises, all over the country.

Wikipedia seems to confirm..

Seeking Tyler, he begins to discover that Tyler has established a secretive underground network of fight clubs nationwide operating under the ethos of Project Mayhem.

The denial you refer to..

                        JACK
            Local 8 just started in Penns Grove.
            And, Bob said he was at fight club in
            Newcastle last week.

                        TYLER
            Newcastle?  Did you start that one?

                        JACK
            I thought you did.

...is, perhaps, the first indication, in hindsight, that Tyler is the Narrator.

