After an accident, you lose your memory, coming to your senses in St. Mungo's Ward - you don't remember the last 6 years, but no one still doesn't said it to you or Draco. Draco Malfoy bursts in on you, for some reason telling you that you're married. You and Draco hated each other at Hogwarts and definitely didn't communicate closely in your memory. Only girls sry

Voldemort won the battle for Hogwarts. The Golden Trio is dead, not all horcruxes have been destroyed, and y/n is one of the few remaining members of the Order of the Phoenix. Draco Malfoy has been a death eater for 3 years, formidable and accomplished in the service of the Dark Lord (but deep down he is very broken and does everything to protect his family, even if it is torture and murder). You are caught by Death Eaters and sent for interrogation to Malfoy (who doesn't like you very much). Having legilimency, he understands that your memories are hidden, which means that you know something important that will either help destroy Voldemort, or promote him, at least briefly protecting his family. And he decides to get information from you at any cost.