Break the Rule (Kings of Heart Book 3) – Lucky Hart

Description:

She has lived only in shadows, but now she must step into the light.
Born and raised by the Baleful, an assassin guild spoken of only in hushed rumours, Zinha is chosen for a dangerous assignment – a game of seduction with a deadly goal that will test everything she’s trained for. The King wishes to invade the neighbouring country of Maetora, but he must first neutralise their ruler – and her dangerous magic.
Zinha infiltrates The Trial of Power, a magical competition during which the Maetorian Heir chooses his consort. She must seduce the Heir, uncover his mother’s secrets and topple their kingdom from within. But Heir Reyher is not what she expected, and neither are the Maetorians. Especially Mateo, a fellow contestant with his own secrets.
As Zinha gains more distance from the darkness of her previous life, doubts begin to surface about everything she’s been told. When rumours of a rival assassin threaten her success – and the lives of the people she has come to love – Zinha is forced to choose between the powerful bonds of her past and the fragile hope of an unexpected future. Because time is running out, and the Baleful live by only one rule:
Succeed or die.