In Deluge the selkie twins, Ronan and Murel, leave Petaybee on a mission to help rescue their friend Marmie, who has been falsely arrested on the orders of a corrupt Colonel. However, the Colonel has more power in the Company than they realized and they end up being imprisoned themselves and taken to the Gwinnet Incarceration Colony. There they have to try to evade the clutches of their old adversary Dr Mabu, an unscrupulous scientist who wants to study their unusual shape-changing ability, and doesn't care how much pain her experiments cause them.
Meanwhile, the powerful and avaricious Company is making another attempt to take over the world of Petaybee for its resources, and the twins parents, Yana and Sean, along with the entire planet, must fight for the independence of their sentient world once and for all...
Precocious twin selkies Ronan and Muriel set out for their heroic third mission (after 2007 s Maelstrom): rescuing an old friend who s been wrongfully imprisoned. Petaybee has been invaded by troops intending to arrest the twins parents and others for aiding Marmion de Revers Algemeine s evacuation of the endangered inhabitants of Kanaka. Marmion herself is languishing in the Gwinnet Incarceration Colony. Ronan and Muriel dodge the soldiers and hitch a ride with space-faring deep-sea otters to reach Versailles Station, Marmion s home base, where they hope to beg influential Federation friends for help. Instead they wind up incarcerated with other youngsters at Gwinnet s Camp Neverland and cruelly tortured until their special skills and friends (including Zuzu, a telepathic cat) help them survive a tsunami and volcanic eruption and complete their mission. This concluding volume of the twins trilogy will primarily appeal to young, animal-loving SF fans.