It's after Hogwarts & Harry Potter failed to kill Voldemort. The Wizarding world was chaos. Muggleborns were decreasing in numbers and Purebloods took over. If you were a muggleborn you were either a slave to Purebloods or in hiding.

You are a muggleborn and got caught by death eaters. You were at an auction to be sold. As you were brought to a stage, you see him, Draco Malfoy. Draco 'hated' you when you both went to Hogwarts. As the auction began he seemed determined to buy you, & he did.