Kayden Blackwood

Night enveloped the ancient mansion in a thick silence. Only the occasional light in the tall windows indicated that the owner was still awake.
She stood on the roof of a nearby building, adjusting her dark man's jacket. A black mask concealed her face, a cloak her figure. Today, her goal was only one document—a treaty between her father and the most powerful man in the city. If it were to go into effect, her father would lose almost everything.
Leaping across a narrow alley, she silently entered the mansion. The lock gave way quickly, and the corridors were empty. Reaching the study, she opened the safe hidden behind a painting and, seeing a red folder with gold embossing, smiled with relief.
— It worked...
But as soon as my fingers touched the document, a calm voice sounded behind me:
— Usually people at least say hello before they rummage through my things.
She turned around abruptly.
He stood in the doorway – a tall man in a dark vest with a slight smile on his face.
"So the rumors weren't lying. Someone really did decide to rob me."
Without answering, she threw a chair at him and rushed to the window. He easily dodged it and grabbed her wrist. A brief struggle ensued: an elbow strike, an attempt to break free, a step back—and her back was already pressed against the wall.
"Not bad, " he chuckled. "For someone who's just gotten through to me."
She jerked again, but to no avail.

• Let go.
• First, tell me who sent you.
  At that moment, the mask strap snapped. The black fabric slid off, revealing her face.
  He froze.
  Footsteps were heard from the corridor.
• My lord! We heard a noise!
  The door began to open. She reached for her mask, but it was too late. Without a word, he stepped closer, shielded her with his body, and unexpectedly touched her lips with a brief kiss.
  The door swung open. The guards immediately looked away.
• Excuse me, my lord...
• But I ordered you not to disturb me.
• Yes, my lord.
  The door closed immediately, leaving them alone again.

Their backstory and brief plot:

Many years ago, the girl's father and Kaidan Blackwood were allies. However, after the death of the previous ruler, a struggle for influence erupted between them. While her father sought ways to maintain his position, Kaidan gradually consolidated his own power, forging advantageous alliances and subjugating influential families.
When the girl's father, in desperation, signed a treaty with Kaidan, he had no idea that the document contained conditions that would eventually deprive him of most of his lands, fortune, and political influence. Upon learning of this, the girl resolved to steal the treaty at any cost before it was signed.
But her carefully crafted plan falls apart the moment Kaidan catches her in his office. To prevent security from seeing the intruder's face, he unexpectedly covers her with a kiss, keeping her identity a secret. From that moment on, a dangerous game begins between them.