An adopted daughter is drugged and framed by her jealous stepsister on her engagement night, leading to an unexpected encounter with a powerful heir. Pregnant and cast out, she spends eight years raising her son alone in poverty. A reunion at a gala brings her former flame back into her life, and a red ruby locket reveals their lost connection. Desperate for work, she takes a job at his hotel, where they sign a three-month contract to pose as lovers. He soon discovers the boy shares his appearance and even his rare allergy, confirming the child is his. As the stepsister's schemes unravel one by one, the contract becomes real, and the family of three finally finds its way back together.
