Valeria Anson has always been one in a set, her and her twin brother sharing everything from clothing and toys to their mother's womb.

But the one thing they didn't share was the searing image of their mother's brutal murder, one that haunts Valeria every night without fail.

Almost a decade has passed since their mother's untimely demise, and despite their father's role as Viscount and Chief of the King's Imperial Force, the masked killer has never been caught, still free to roam the snowy streets of Nieve.

Although her father and brother have given up hope of locking the killer behind bars, Valeria refuses to let the case go. But the road to the truth is a lofty one, her secret investigation leading her to Alias Black, the most infamous hitman in the kingdom. While associating with the dreaded killer goes against every one of her beliefs, the heartless assassin may be the key to finally tracking down the masked murderer who lurks in her dreams.

Lying to her family by day and working with Alias Black by night, Valeria must now walk the thin line between right and wrong, justice and revenge, dreams and reality. As the unlikely pair slowly crack the case, they unravel a truth they never could have imagined—not even in their darkest nightmares.