Some ultra-hard sf, ultra-far future, as with the previous story by Wilson. However, Watts’ is slightly less successful in taking on the challenge of presenting the story from a female protagonist, not quite getting an emotional depth of character.
Earth is long-dead, but humanity lives on, albeit in the service of those less than but more than human, constantly expanding the sphere of galactic conquest by building wormholes. Having created a wormhole, the humans have to flee to avoid being caught up by those hard on their heels.
As in the Wilson story, the humans achieve longevity by spreading their lives across centuries by living in short bursts – both authors using the term ‘saccade’. Whilst Wilson’s protagonist is uploaded (but is able to retain and sustain emotional needs), Watts’ protagonist has physical needs which she is able to satisfy both by herself (having her ‘jill off’ comes across very strongly as a female character written by a male) and with her son.
The son is only partly such, a creation of ‘the chimp’, the AI which controls the construction ship. There’s an interesting troilistic relationship here, with the chimp directly linked to the son, who has been created in order to spy on his mother.
The drama is set up when the system in which the latest wormhole to be built has a very, very anomolous entity. So anomolous that it is beyond the AI’s coding to incorporate into its decision making, and the mother has to find ways to persuade it not to start a destructive build near a colossal, biological, sentient creature – less an Island but more a Dyson Sphere.