Two children are divided by centuries, countries, language and religion, though each of those things also unite them, aided by the principle of “aquatic memory” that dominates a novel that is always absorbing and often painfully affecting. The first is Arthur Smyth, born on the foreshore of the River Thames in 1840 to an impoverished and terrified young woman, and given his name by the “toshers” – shoreline scavengers and foragers – who gather around her and pronounce him King Arthur of the Sewers and Slums. Arthur is both blessed and cursed by a phenomenal memory, and although grinding poverty and a vicious, violent father blight his early life, his intellectual gifts allow him first to find work at a printing and publishing company and then at the British Museum.
In 2014, at the edge of the Tigris, Narin lives in a small village in which her Yazidi community forms an even smaller, and increasingly marginalised, part. Cared for by her grandmother, a water-dowser and storyteller, she is losing her hearing and anticipates that soon, her world will fall silent. Before then, however, she is to travel to Iraq to be baptised in the holy valley of Lalish, the more usual home ceremony having been made impossible by the encroachment of the bulldozers working on a vast dam.
The links between the two young characters will take several hundred pages to unfold, although the narrative is seeded throughout with hints and signs, and given additional help by a determined contemporary hydrologist, Zaleekhah, whose passion for uncovering the world’s buried rivers is providing a distraction from her broken marriage.
It is, by evident design, a complicated structure and a busily peopled milieu: the reader is presented with a portrait of ancient Mesopotamia and the destruction of Nineveh, the roiling, stinking streets of Victorian London and the far more recent persecution of the Yazidis, including the massacre of thousands in Sinjar at the hands of Islamic State in 2014. It would be possible for these juxtapositions – meat pies, pickled whelks and a cameo from Charles Dickens giving way to child abduction and enslavement – to strike a jarring, and even twee, note. But Shafak is a novelist whose interest in mapping the intricately related world and its history goes beyond literary device; her determination to trace connections is a matter of ambition, not merely aesthetics.
It is also a novel that reflects on the persistence of global inequality: the image of the apocalyptic flood appears in the Epic of Gilgamesh before the Bible; the lapis lazuli tablets on which the poem is carved end up in Victorian imperial museums; the displaced and captured child from a war zone might represent the chance of a healthy new organ to her rich, western counterpart.
Like Arthur – who is modelled on the real-life assyriologist George Smith, who taught himself to decode cuneiform tablets and first translated Gilgamesh into English – Shafak is a voraciously eclectic reader. The reign of Ashurbanipal, John Snow’s fight to prove cholera outbreaks originated in London’s tainted water supply and not its foul air, the science behind changing hydroclimates; all find their way into her novel. You can feel overwhelmed by the sheer volume of information, and the almost breezy briskness with which it is relayed, but it is balanced by the delicacy of Shafak’s observations about human dynamics, the furtiveness of her characters’ most deeply held emotions and desires.
• There Are Rivers in the Sky by Elif Shafak is published by Viking (£18.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply
