Excession   by Iain M. Banks

On top of that this book magnificently spans and manages to connect a breathtaking range of scales. Suddenly, one day, a black sphere re-appears in the cosmos (before you ask, this is nothing like 2001: A Space Odyssey). The book then explores the effect that this inert object has on a fleet of ships, individual ships (in Banks' Culture universe, ships have souls, remember), ship's avatars, ship's crews, and on individual human beings caught up in circumstances that only Banks' imagination could have invented. It's a wonderfully rich universe of eccentric ships and forty-year suspended pregnancies, human/human mixed sex and human/ship and ship/ship conflicts.

Despite the out-of-this-world proportions, everything is plausible and believeable. The story flows along with Banks' usual lucid style.

Totally and utterly brilliant.