Froggy was akumatized and Hawkmoth made a sentimonster... Strikeback! Ladybug used the horse miraculous to go to the train where Felix was but she thought it was Adrien, she ran in and bumped into Felix

Ladybug: "Oh Adrien! Mind if you help me?" She smiles

Felix: "Of course" he has a devious smirk on his face

Ladybug: "Adrien Agreste, here is the miraculous of the dog" she hands it to him "When the mission is over you will hand it back to me, can I trust you?"