The Culture/Excession/YMMV


 * Complete Monster: This + Boisterous Bruiser = The Affront's Hat.
 * Crazy Awesome: The Sleeper Service
 * Fridge Logic: The big trick to talking to the Excession is that it only engages in one-on-one private conversations, probably so as not to cause an excession. Which is exactly how any ship in the Culture would act if they were an excession. The Grey Area is the only ship that may have worked this out.
 * Forcing conversation ends badly. The Elench didn't really survive that when they tried. And that drone that carved that message into the side of a ship that was destroying it did not really fare well in the end either.
 * The first Culture ship to report on the Excession mentions attempts to talk with it, which is how it can later be addressed by its callsign, "I". The rest of the Minds involved quickly realize that communication with and studying the thing is less urgent and/or more dangerous than the immediate problem of dealing with how other civilizations will react to finding out about it.
 * Game theory (specifically, the scenario of the open-ended iterated prisoner's dilemma) suggests that the optimum course of action when first meeting an entirely unknown entity is to lead off with a minor but clearly benign gesture, then wait to see what your opponent does, then mirror his responses re: cooperation or conflict. Now think back to what the Excession was behaving like throughout this entire story...
 * Directly lampshaded by the Sleeper Service at the end when it realizes that the Excession is merely echoing its own gesture re: giant threat display.