The Outcast Blade — Jon Courtenay Grimwood

As the Byzantine and German emperors plot war against each other, Venice's future rests in the hands of three unwilling individuals:

The newly knighted Sir Tycho. He defeated the Mamluk navy but he cannot make the woman he loves love him back. Tortured by secrets, afraid of the daylight, he sees no reason to save a city he hates.

The grieving Lady Giulietta. Virgin. Mother. Widow. All she wants is to retire from the poisonous world of the Venetian court to mourn her husband in peace. But her duty is to Venice: both emperors want her hand in marriage and an alliance with Europe's richest city. She must choose, knowing that whichever suitor she rejects will become Venice's bitterest enemy.

Lastly, a naked, mud-strewn girl who crawls from a paupers' grave on an island in the Venetian lagoon and begins by killing the men who buried her.

Between them, they will set the course of history.