FL is a beautiful, blond foreign princess sent to marry the grand duke of a neighboring kingdom who's also a secret illegitimate son of the king (ML). On the way to his estate, her entourage is attacked by monsters, and she goes missing on a snowy mountain. ML is tasked with finding her no matter what. Despite the princess' country offering to send people to help or even a portrait, ML refuses (but why?). After several days of searching, he's "saved" from a monster by a red haired woman who seems to have lost her memories (no details given on how she managed to do this with no weapons and tattered clothes). He brings her back to his estate as his benefactor and decides to help her recover her memories. Meanwhile, everyone else in the estate thinks she's trying to seduce him and subsequently treat her like shit. Although the woman is clearly from the princess' kingdom given her accent, none of them think she could be the princess because of her hair and eye color. Ok, sure, but why would no one even question if she was part of the royal entourage? They don't even let the other kingdom know they found this random woman from their country wandering around the mountain. Some time later, they finally find a body after the snow melts that they mistake as the princess (it was actually her lady in waiting). Despite the princess being beloved by her family and kingdom, they allow her to be buried at the estate of a man she had never met and hadn't even married yet instead of asking the body to be repatriated, and no one from her kingdom comes to the funeral. By this time FL has fallen head over heels in love and confesses her feelings now that there's no chance of him marrying the dead "princess". ML tells her he has no feelings for her, but he agrees to marry her anyway for 1 year to avoid getting hitched to the daughter of some count he doesn't like who's trying to place him on the throne as a puppet ruler. After marriage, he basically treats her like a mistress but refuses to ejaculate in her because he doesn't want children for unexplained reasons. Over time, he becomes increasingly possessive, obsessive, and jealous, going as far as to assault her in a greenhouse and then lock her in an abandoned room where his mother hung herself after witnessing FL laughing with a gardener. He even tells the servants not to give her food and water while she's locked up and then leaves for a monster expedition for like a month (dude, are you trying to punish her or kill her??). While locked up, FL realizes she's pregnant and decides to run away since ML said he'd kill the baby if she ever got pregnant.