I've seen many people on this forum say that the plot isn't the strongest side of Dishonored. So Iet's discuss our less favourite parts of the plot: speech lines, character traits, plot inadequacies - everything.
I'll start with my four pet peeves.
First two are minor - just some things that I'd like to be developed more.
1) It's a pity that such an interesting motive as Sokolov's obsession with the Outsider didn't get enough attention. I expected Sokolov to react after he had seen Corvo's mark and had met Piero, who was also connected very closely with the Void.
2) I also expected Pendleton to comment on Lady Boyle's portrait - to try to guess which of them she is, based on his (supposed) sixual exploits with Boyle's women.
3) I strongly dislike that Callista calls Corvo assassin before the Campbell mission. He is not yet. He has always been Lord Protector.
Though in the description of TBW Corvo is called "the Royal Bodyguard and Assassin" (for the first time, as far as I know), so, maybe that really was in his job description. But then she says that he had been a bodyguard before he became an assassin.
4) And this one I hate with passion. It is Daud saying "I forgive you" to Billie. It is so out of character! I can imagine him (in low chaos) either killing her, which would be a gift, or just sending away as a thing that disgusts him and interests no more. To forgive a traitor that had been your favourite student, but then not only tried to kill you, but also caused deaths of many of your people - what is he, a saint? I don't think that him expecting one of his people to try to kill him is relevant in her case.