The immortal man Cheyne marries Chloe, the infamous crazy woman, due to a scheme. He tries to stay away but discovers her rare bloodline can boost his cultivation, so he secretly protects her. As she repays him while hiding her true nature, her scheming sister pushes too far, and Chloe unleashes her power to protect her beloved.
Marble Freeman, a herbalist from the mountains, saves Declan Burnell's life by chance. To gain access to the Burnell family's herb-cultivation secrets, Marble reluctantly agrees to a 99-day marriage contract with Declan, who is also coerced into the arrangement by his grandfather. After the contract ends, they part ways, but with an agreement that Marble will seek revenge for her mother before they contemplate a possible reunion.