They don't do anything significant. I haven't been following the story either (is there anyone who does?),
Personally I read it all
It wasn´t bad, just everytime the same. In fact, I was waiting a surprise or something, but nothing.
For those that don´t want to read it, it´s just something like this:
SPOILERS TiQal is being destroyed, and a chaman tells you to journey to talk with the gods, to save the city. You then go place to place, to every pyramid always learning things and making offerings. You later learn than TiQal is being like that because your people isn´t as it should be: They have forgotten their history, they are not brave, etc. The gods tells you to guide your people, and you return as a king. TiQal is saved and all people is in peace. END
I don´t remember it fully, and I don´t know if those are the best words, but it´s something like that.