It is mostly politics and back stabbing of nobles. It does not have a lot of science and their are no aliens. The book builds and because the characters are well developed, gets better the longer it goes on.

That is because it is mostly a political book, with Guilds, Courts, Emperors, and Great Houses. I listened to the whole book and will be buying the sequel, but had it been a different author, I might have given up within the first three to four hours. SORRY, I GOT DISTRACTED THINKING ABOUT SEX The book is a tiny bit Dune, Game of Thrones, Foundation and The Last Empress. The humor is fairly steady throughout the book without being overwhelming. SCALZI humor includes giving funny names to ships, such as the following: TELL ME ANOTHER ONE, I THINK WE'RE ALONE NOW, IF YOU WANT TO SING OUT, SING OUT, YES SIR, THAT'S MY BABY and it's sister ship NO SIR, DON'T MEAN MAYBE. YOUR ALWAYS ALONE INT HE MEMORY ROOM AND NEVER ALONE IN THE MEMORY ROOM This is filled with lots of LOL moments and some great funny characters. When it's discovered that The Flow is moving, possibly cutting off all human worlds from faster-than-light travel forever, three individuals - a scientist, a starship captain, and the empress of the Interdependency - are in a race against time to discover what, if anything, can be salvaged from an interstellar empire on the brink of collapse. Just as a river changes course, The Flow changes as well, cutting off worlds from the rest of humanity. The Flow is eternal - but it is not static. It's a hedge against interstellar war - and a system of control for the rulers of the empire.

Humanity flows away from Earth, into space, and in time forgets our home world and creates a new empire, the Interdependency, whose ethos requires that no one human outpost can survive without the others. Our universe is ruled by physics, and faster-than-light travel is not possible - until the discovery of The Flow, an extradimensional field we can access at certain points in space-time that transports us to other worlds, around other stars. 2018 Locus Award, Best Science Fiction Novel

The collapsing empire