Book one:
- Book one is generally pretty light on bad feelings, but H.I.V.E.mind's general misery over the way he's treated by the other members of the staff is pretty depressing.
- Not to mention the fact that at the end of the book, he's given an emotional lobotomy by Pike for daring to feel feelings.
Book two: The Overlord Protocol
- At the start of the book, Wing is told that his father died, and he will be allowed to attend the funeral. Wing doesn't react much to this, because, he says, his father died emotionally years ago, and he was actually raised by someone else.
- Even though an explanation is given later, Wing's death is very shocking, and Otto's heartbroken attitude that he carries through the rest of the book is equally awful. The other students' reactions, particularly Shelby's, are also painful to watch.
- The villain's motivation. Cypher's wife, Xiu Mei, was killed a few years ago and he has reason to believe Nero did it. After that, Nero, as far as he knows, kidnaps his only son for reasons he can only imagine.
- A much milder example, but the flashback sequence shows that Nero really did care very much for Xiu Mei, and it seems he's lost a lot of friends over time.
Book three: Escape Velocity
- Even though it works out in the end, Nero and Raven doing their best to protect each other in London, and failing is pretty distressing to see.
- The revelation that Otto is a clone of Number One created by Overlord. It's clear that this connection is irredeemable and no family can be found there. On top of that, all of the things that he was proud of about himself, such as his intelligence and resourcefulness, are designed to allow him to be a more useful meat sack for someone else. He was designed to die.
- Otto's resignation to the fact that his own death is what would be best, and asking Nero to kill him.
- H.I.V.E.mind sacrificing himself so Otto can have his body back.
- The Contessa's slow realization that she's fighting for something she can't support, and giving her life to protect the school.
- After the climax, Otto's preoccupation with his own purpose, and the realization that he'll never have a normal family. He doesn't tell the other students because he doesn't want them to think of him as different.
Novella 3.5: Interception Point:
- The fact that Sebastian Trent is able to so easily gain control over Otto and lock him out of his own body. At the beginning of the book, he's enthusiastic about his new abilities to the point that he's overusing them, but by the end, he's sworn off of them for a while. This persists into Dreadnought.
Book four: Dreadnought:
- This book sees our first view into Raven's background, and it sucks: she was held prisoner at a camp for children in Siberia where they are forced to learn to fight. Little Natalya tries to get away, but is ultimately caught by Pietor Furan.
- Minor, but Shelby's visible distress at being locked in a cell hurts to see, since she's usually so inflappible.
- On a similar note, Raven is shot in the leg early in the book, and spends the rest of the volume in pain.
- The ending. Otto is captured by the US government, after arguably saving the entire United States.
