An Yang is attacked while visiting a mountain temple to pray. As she flees for her life, her sworn enemy, Shang Shaoyuan, saves her.
Afterward, she finds a book of prophecies.
It says she has no more than three months to live, and that the only way to survive is to form an alliance with Shang Shaoyuan.
If it's for her life, then she'll form an alliance.
Later, the book says she must move into Shang Shaoyuan's home to survive.
If it's for her life, then she'll move in.
After that, the book says she must marry Shang Shaoyuan if she wants to stay alive.
They're already living together, so she might as well marry him, as long as it keeps her alive.
One day after they marry, she goes to Shang Shaoyuan's study and sees him marking up a prophecy book with a pencil, a book that looks incredibly familiar.
What prophecy? It was just a trick that man came up with to win her heart.