The Order. The Immortals, #1

Prepare to be captivated by a world where immortal guardians clash in a battle for humanity's soul. As one of the oldest and most skilled Guardians of the vampiric Order, Celeste has spent centuries shielding humanity from the ruthless ambitions of the fae. Her resolve has never faltered-until a mission brings her face-to-face with Kailen, a fae who defies every truth she's sworn to uphold. When Kailen risks his life to protect a human from his own kindred, Celeste's certainty shatters.
Duty demands she condemn him. Her heart-long locked behind iron walls-whispers otherwise. As dark forces stir and enemies rise from the shadows, Celeste must decide who is truly worth her trust. In a world built on secrets and betrayal, choosing wrong could doom the mortal realm. and destroy the one connection she never expected to find.