It was one of the less glorious incidents of the Idiran wars that led to the destruction of two suns and the billions of lives they supported. Now, eight hundred years later, the light from the first of those ancient deaths has reached the Culture's Masaq' Orbital. For the Hub Mind, overseer of the massive bracelet world, its arrival is particularly poignant. But it may still be eclipsed by events from the Culture's more recent past. When the Chelgrian Ziller, a composer of great renown now living in self-imposed exile, learns that an emissary from his home world is being sent to Masaq' Orbital, he fears the worst: that the Chelgrians want him to return. A considerable debt is owed to the Chelgrians, but Ziller is an honoured guest on their world and the Culture would not force him to leave.They know that they are facing a slight diplomatic problem. However, Ziller is not the only thing on the Chelgrian emissary's mind. If his mission is successful, it will illuminate the Culture's future as well as its past.