The novel “The Hydrogen Sonata” by Iain M. Banks was published for the first time in 2012. It’s part of the Culture series.

The Gzilt civilization contributed to the formation of the Culture but in the end it didn’t join. After 10,000 years, the Gzilt are going to move to a different plane of existence called the Sublime and that’s supposed to be an occasion to celebrate. However, other civilizations have sent spacecraft to take possession of what Gzilt are abandoning creating tension and the Zihdren-Remnant, what remains of an ancient civilization that influenced the Gzilt, sent a mysterious message.

Vyr Cossont is a musician who, on the eve of the transition to the Sublime, is reinstated in the Gzilt army. Why are the Gzilt authorities interested in her past encounter with a member of the Culture? What is the meaning of the mysterious acts of war involving the Gzilt? Various Minds of the Culture officially want to celebrate the Gzilt passage to the Sublime but actually are investigating these strange events.