In Venice, Frances Croy is working to leave the previous year behind: another novel published to little success, a scathing review she can't quite manage to forget, and, most of all, the real reason behind her self-imposed exile from London: the incident at the Savoy.

Sequestered within an aging palazzo, Frankie finds comfort in the emptiness of Venice in winter, in the absence of others. Desperate to rediscover the success of her first novel, the one by which all her other work has been judged, she attempts to return to the page - ignoring the strained relationship with her best friend, the increasing phone calls from her editor, demanding the final book of her contract, and the growing fear that the end of her career is imminent.

And then Gilly appears.

A young woman claiming a connection from back home, one that Frankie can't quite seem to recall, Gilly seems determined for the two women to become fast friends. Frankie finds herself equally irritated and amused by the strange young woman before her - but there's something about her that continues to give Frankie pause, that makes her wonder just how much of what Gilly tells her is actually the truth.

Those around Frankie are quick to dismiss her concerns, citing her recent fragile state and what took place that night at the Savoy. So too do they dismiss Frankie's claims that someone is occupying the other half of the palazzo, which has supposedly stood empty since after the war. But Frankie has caught Gilly in numerous lies, has seen the lights across the way, has heard the footsteps too-and what's more, knows she isn't mad.

Set in the days before and after the 1966 flood - the worst ever experienced by the city of Venice - the trajectory of the disaster that forever altered the city mirrors Frankie's own inner turmoil as she struggles to make sense of what is and is not the truth, ultimately culminating in a tragedy that leaves her questioning her own role and responsibility - as well as her sanity.