A Fierce Princess (The Poisoned Pawn Duet Part I) - A Poisoned Pawn Series, #1

Her life is a lie. And one man has the power to reveal all her secrets. The world sees a princess. But that's not all Princess Susanna is. When her mother's crown was stolen after the queen was killed, Susanna ventured into the dangerous world of the dark web to find it. Now she spends her nights following leads and hunting criminals under an alias. In her pursuit of justice in this seedy underworld, she uncovers a royal assassination plot. The target: a prince.
The catch: he has no idea he's a member of a royal family. Susanna can't help but act on her instincts to protect the man. Only the more she gets to know him, the harder she starts to fall for him. But can she trust him with her secret? And more importantly, can she trust him with her heart?