aCoS was when we first see her, but Alviarin mentions many meetings with her before.
Clearly, she has been there. If her presence in the Tower is unnecessary for her to control the BA while deposing an Amyrlin, she doesn't have to be there at all. I think it is clear that she has been in the Tower since the events of tSR.


What do you mean an obscure sister will be known by another obscure sister? Alviarin, in her PoV when we first meet Mesaana, mentions sisters who had very few or no friends at all. The last category will have no one who knows them.
For example, remember the Brown who comes to coach Egwene on what she has to say before she is raised by the Hall in tGS? Egwene surmises that she probably lived in some isolated corner of the Brown Ajah, immersed in her studies. What if Mesaana is one such sister?


We are specifically told that the Reds were warned to to replace the absent Sitters (all three of theirs were absent) so that they could have a say on who is Amyrlin.

Now, if this were a possibility, then I don't see why Mesaana/Tsutama did not defy the Hall's wishes and send in new Sitters. The Hall could have done nothing about it. Yes, the other Ajahs would have turned on the Reds, but that would have served Mesaana's purposes well, no?

At the least, it would have ensured that Egwene's reign would be filled with trouble from the Reds. Why didn't Mesaana work for that?

If Tsutama is who she says, however, her actions make sense, as an attempt to preserve the Red Ajah.