Divergent series book 3 "Allegiant" rewrite

First and second book were well written but the last book was rushed, had gaping plot holes and the characters made stupid decisions. Sacrifice for the sake of sacrifice is ridiculous, plain and simple. Don't kill off your character because the theme of the book is sacrifice... Kill her off for a good reason! Seriously. Did we just forget that truth serum exists? You didn't think a few drops in David's morning coffee, getting the codes and tying him up for a few hours was a better idea than "oh gee damn, we don't have the codes, guess someone's gonna have to commit suicide now!". It was like a completely different series to the first 2 books. None of the things that were important in book 1 and 2 were treated with any kind of respect in book 3. Come on Roth. I expected better of you.