And that's when Tia will let her guard down in an unbelievably plot-convenient but out of character fashion, at which point she'll be kidnapped and dragged off somewhere with improbable ease, where the Empress will stupidly show up in person to gloat, then just in the nick of time Perez will show up with the proverbial cavalry, thus incontrovertibly tying the Empress to crimes she can't get away with.
God I hope the author doesn't follow that tired old cliche, but I've seen near-identical iterations of the same trope so many times now...