Holston and Proper Gauge, were both compelling character studies set in an intriguing science fiction world, but the third was where the plot manifested in a clear way.
The Silo's newest sheriff is finding that politics play a bigger role in her job than she ever anticipated. That fact makes the recent deaths of potential allies look incredibly suspicious, and she begins to investigate. She quickly exposes hints of a deep conspiracy. But its perpetrators just as quickly turn their attention to her unwelcome meddling.
With this third volume of Silo, the narrative point-of-view transfers to a third character. New sheriff Juliette is the most compelling protagonist yet -- smart, skilled, and shrewd. Getting inside her head doesn't necessarily lead to any new revelations since her introduction in the previous short story, but it does make the reader cheer her on even more strongly. You hope that she'll be the one to begin righting the injustices depicted in the previous volumes.
Casting Off really defines the stakes that the series as a whole is playing for, and also hints at which characters will be involved in it going forward. The short stories had been serialized to this point, but this is where the story really makes the turn from serial to novel. And it manages to do all this despite the fact that the reader is already aware of a key secret that the protagonist is trying to uncover. This sort of insider information should serve to deflate a lot of the tension from the tale, but that tension is replaced (and then some) with the suspense of whether Juliette can outrace the conspiracy she's poking into.
At this point, Silo would have to do a colossal belly flop to make me turn back. This story was my favorite yet. I give it an A-.