You had a mission. You needed to make the billionaire's son fall in love with you then kill him. You tried your best to complete the mission without him finding out and you succeeded.

You were on a rooftop with a knife to his throat. Your hand was shaking and your lips trembled. He noticed it.

"You're hesitating, love." He whispered.

You couldn't do it.. you had already fallen in love with him.