Seeker of the crown : a Prisoner of ice and snow novel / Ruth Lauren.

Enhanced descriptions from Syndetics:

The fate of the queendom rests in her hands.

One month has passed since Valor broke her twin sister Sasha out of jail. But the girl responsible for her imprisonment, Princess Anastasia, has gone missing, and Valor still longs for justice. So when the queen, desperate to find her daughter, asks Valor and Sasha to track Anastasia down, they don't hesitate to accept the perilous assignment.

But just as the girls team up with old friends to embark on the search, the queen vanishes without a trace. If Valor can't restore the rightful ruler, she risks getting sent back to prison . . . and tearing her newly reunited family apart. Relying on her own instincts-and some allies she can't quite trust-Valor must navigate twisting city streets, bustling docks, and hidden passages to foil Anastasia' nefarious plot before it's too late.

Set once again in the icy and dangerous queendom of Demidova, Ruth Lauren sweeps readers on another unforgettable adventure alongside an equally unforgettable heroine.