An ancient people, the Gzilt helped set up the Culture ten thousand years ago and were very nearly one of its founding societies, deciding not to join only at the last moment. Now they`ve made the collective decision to follow the well-trodden path of millions of other civilisations: they are going to Sublime, elevating themselves to a new and almost infinitely more rich and complex existence.
Amid preparations, though, the Regimental High Command is destroyed. Lieutenant Commander (reserve) Vyr Cossont is now wanted - dead, not alive. Aided only by a reconditioned android and a suspicious Culture avatar, Cossont must complete her last mission and find the oldest person in the Culture, a man over nine thousand years old, who might have some idea what really happened all that time ago.
It seems that the final days of the Gzilt civilisation are likely to prove its most perilous.