It’s not too uncommon for an SF story to split itself between different time frames separated by centuries, with the causal links between frames only gradually made apparent – M. John Harrison’s
Light is a well-known example – but the odd structure of Adam Roberts’s
Purgatory Mount still seems pretty bold, as does the novel’s shifting tone from Clarkean far-future SF to gritty dystopian naturalism to earnest moral debates about responsibility and atonement. We begin in that far-future on the kilometer-long starship
The Forward, whose five crew members, all named after Greek gods, are described as “gifted with magic (in the Clarkean sense of the word)” and whose shipboard computer is called a “hal.” They’ve just discovered an enormous alien artifact on a remote planet – a 142-kilometer-high pyramidal structure which so resembles Dante’s mountain in