Crown of Midnight(2013)

Sarah J. Maas

Crowned by Evil.
Bound by Duty.
Divided by Love.

Celaena Sardothien, royal assassin, is the King of Adarlan's deadliest weapon. She must win her freedom through his enemies' blood - but she cannot bear to kill for the crown. And every death Celaena fakes, every lie she tells, put those she loves at risk.

Torn between her two protectors - a captain and a prince - and battling a dark force far greater than the king, Celaena must decide what she will fight for: her liberty, her heart or the fate of a kingdom...