It is a simple but rich concept. Whitfield posits two sapient species: the landsmen (humans) and the deepsmen (essentially mermaids, although in no way romanticised). Ever since the invasion of Venice in the Ninth Century, the kingdoms of Europe have been ruled by hybrids -- children of the union between landsmen and deepsmen -- able to command the loyalty of both the land and the sea. Only landlocked states like Switzerland can afford to ignore the rulers of the waves. The consequence of this is that bastard children like Henry pose a threat to the ruling monarchy and are summarily executed when discovered. As such he is somewhere between a prisoner and a prince.

Anne is Henry's mirror image, the child he could have been. She is a royal child, a hybrid like him but sanctioned and raised on the land. After reading Henry's story, we then read her parallel story. Following immediately afterwards it is perhaps not as excitingly fresh but it is every bit as engrossing. Whitfield's characterisation is rich and precise. Although Anne is closed and guarded where Henry is angry and open both are seeking to steer their lives through the straits of their circumstances and their interior worlds are fascinatingly realised.

Inevitably, after these exhilarating twin narratives of discovery and coming of age which take up the first third of the novel, it slows a little as it reshapes itself. Their stories start to intertwine and In Great Waters then becomes a battle for the throne. All their lives Henry and Anne have been pawns in the games of others but, as the book progresses, they find the agency they have been striving for and when they finally meet, they are able to effect revolutionary change. If that sounds rather too easy, it is because I have excised all the physical, psychological and philosophical barriers that Whitfield shows them overcoming in a way that never seems contrived but rather resonates with their internal strength.

In Great Waters is a delight to read, an elegant and contained work. People frequently profess to like clean, unadorned prose when often what they mean is prose that is charmlessly functional, prose that gets you from A to B without needing you to really to engage. Whitfield is the real deal, her prose is clear like a mountain lake; cool, beautiful, bracing, affording glimpses of great depths. I am extremely eager to see what she will do next.