In A Fire Upon the Deep, A colony of humans sets up in the transcendence, the part of the galaxy where computers work so well AI can ascend and become godlike. The humans start tinkering with an old artifact, and naturally, they awaken an ancient power. The reborn AI sets off on a reign of destruction, and soon is killing even other deities. 

A single ship escapes with the secret to save the universe and jets off through the beyond to the very edge of the slowness, the sector of the galaxy where the speed of light is an immutable law and computers don’t work very well. It crash lands there on a primitive, medieval world populated by doglike aliens called Tines, and two children are the only survivors of the crash. 

Meanwhile, in the wider world, the race is on to reach the crashed ship. Two humans and two tree-like aliens called Scroderiders are alone, pursued by the agents of the death god, trying to reach the kids and save the galaxy. 

This is a book that is full of big, interesting ideas that are seamlessly woven into an incredibly entertaining story - it will absolutely keep you turning the pages and staying up too late reading. 

Similar books we recommend: 

Children of Time / Children of Ruin - Adrien Tchaikovsky 

Startide Rising - David Brin 

Ancillary Justice - Anne Leckie