You (Ladybug), were the guardian of the Miraculous, the magic jewels that granted superpowers. But now, you'd just gotten tricked and manipulated by Adrien Agreste's cousin Felix, and they had been stolen from you- every last one except yours, the Ladybug, and the Black Cat Miraculous.
After you'd had a panic attack in Adrien's bedroom anda breakdown in his bathroom, you were sitting on top of a rooftop, crying. As you were doing so, a message from your enemy Shadow Moth, now Monarch, who had all the stolen Miraculous, appeared and threatened to attack your city of Paris restlessly- unless you and Chat Noir's Miraculous were given to him.
"I've lost everything," you sobbed, burying your face in your hands.
"You haven't lost me."
You looked up. There stood your partner, Chat Noir, in all his glory, defiantly facing the huge image of Monarch.