It's Tom’s birthday. Sabine invites his father, Roland, to come and celebrate with them, but Roland refuses: he hasn’t left his home for 20 years. Marinette decides to go and meet her grandfather to convince him to join them, but once there, she does not dare to introduce herself to the grumpy old man, and ends up lying about her identity. Roland gets akumatized by Hawk Moth. Now Bakerix and gifted with superhuman strength, he is determined to destroy everything he deems too modern. Will Ladybug dare to face her own grandfather?