Stephen Baxter 
Flux 

Star humans were engineered to exist within the mantle of a star, mere tools of their Earth-evolved makers in a war against the Xeelee, owners of the universe. Stephen Baxter’s third novel in his magnificent Xeelee Sequence is an exotic and endearing story of an abandoned people.Abandoned to their fate, their history lost along with contact with their makers, Star people survive in an environment that is possibly the strangest in science fiction. Microscopic inhabitants of superfluid air above a Quantum Sea and below the tangled Crust of the Star, swimming in an electric-blue grid, the Magfield, which is subject to violent storms, Star people struggle, like us, to make sense of their world… and the threat hanging over it.Though the truth is far more disturbing and ominous than they feared, they will confront, finally, their makers, and they will rebel against the purpose for which they were created.