The super-clever Trebians need Planet Earth. Si Trool, a brilliant young Mindminder arrives with orders to convince the human race to self-destruct. Armageddon begins, but Si is a hedonist and, despite her contempt for human behaviour, beams down to seduce Liam Young, a philandering government official. The first orgasm achieved by a Mindminder increases Si's already remarkable powers but her timing goes horribly wrong and she must beam up to her ship still coupled to Liam. Then she discovers she is pregnant Certain that she will be rejected by fellow Trebians, Si collects a dozen useful human survivors together and hides with them. Acceptance makes her feel protective and she works secretly to keep the group safe from marauding Trebian machines, hostile bands of other survivors and 'The Incorrigibles' - a bizarre force of ancient minds, who seek the death of Si's half-human, half-Trebian baby to re-establish dominance. To win these battles without revealing her whereabouts or status, Si needs more power. Luckily, Liam arrives but, although a brilliant lover, he is arrogant - and wants to be in charge. If she and her baby are to survive, Si must combine her Trebian genius with many of the human characteristics she detests