A gu doctor has three rules: never fall in love, never use forbidden techniques, and never love an enemy.
She broke every one.
To save her older sister, she signed a contract to treat the poison-ridden young heir of her enemy's family. She promised herself she'd only save his life, not fall for him. But as she kept treating him, she ended up stitching her own heart to his.
Worst of all, she planted a Heartbond Gu in him: they would live and die together, and there was no way to undo it.
He said, "You're ruthless."
She said, "The best thing I ever did was be selfish with you."
