In a post-apocalyptic Scotland ruled by women, Solem escapes from Man Camp 7, helped by a woman called d104a. He and a 'clonie' called Rea hope to reach the 'Island'. How could he have known that this was all engineered as part of the Parth Path's parthenogenesis programme to create the Immortal Controller, an invincible leader whose clones will rule forever?
On the Island, he is haunted by memories of an idyllic childhood as 'Peter', on a reservation with his friend, wee Moira, before his family was brutally slaughtered by Parth Path wardens during a 'clearance'. He struggles to rediscover happiness with Rea.
Sara, a mysterious girl next door, falls for Peter, as he now prefers to be called again, though only shows this by helping Rea. Meanwhile, Moira, still yearning for her childhood sweetheart, after being sent to the Parth Path School, ends up as Director and as such is on the Parth Path Council. She joins d104a, really the brutal man camp Commandant, to collect Rea's baby from the Island, It turns out that little Mary is the genetically-contrived and much-awaited 'Special Child' of the parthenogenesis programme, Her clones are detined to rule forever as the 'Immortal Controller'..
One of d104a's bullies kills Rea. Moira, horrified, shoots d104a. Meanwhile, Sara escapes with Mary to the mainland, vowing to protect Peter's child at all costs.
At first Peter blames Moira for Rea's death, but soon their past friendship is re-kindled. They make love, but are tricked by Matt, the father of Sara's brother, and whose son was killed by Moira's wardens, into believing their lives are in danger. Whilst Peter is told to hide in a cove, Moira is taken to a wartime hideout where she expects to meet up with Peter. Instead she's cruelly raped by Peter's reservation rival, Luke... Matt's revenge for the death of his son. But Moira escapes and kills Luke, returning to the mainland to seek out Peter. Peter emerges from the cove to find Matt, in his rage, has also massacred all survivors of the Island community apart from Angela, Sara's taciturn mother. He leaves the Island with her, hoping to find Mary in the City of the Castle (Edinburgh), but is warned against this. Instead, he finds Moira, and together they flee south of the wall that defines Parth Path territory ('Parthpathia') to start a new life in the 'wilds'. Sara, meanwhile, living in the castle with Mary and a clone of elderly Controllers, is befriended by two old maids who knew the First Controller, the lesbian scientist who started the Parth Path project. She learns things from the 'Shrine', which houses the First Controller's computers, that prepare her for what's to come.
When an epidemic of Scarlet Fever decimates the population, killing the Controllers and Moira, Peter, beside himself with grief, sets off for the City with one bullet left in his gun to kill Sara for conniving with the Parth Path and taking Mary away. However, he discovers a young woman, now Controller herself, and wise way beyond her years, who has been a perfect mother for his daughter. Sara had discovered that the First Controller wanted to abandon the parthenogenesis programme in favour of natural selection but was murdered by her minions. Peter now realises that only he and Sara, by working together, the 'yin' and the 'yang', can help society to start all over again.