Episode Title:
Backwarder.
Episode Description:
Master Fu sends Wayzz to fetch Marinette after he falls ill and tasks her with delivering a prescription for medicine he needs to the local pharmacy and a love confession to his old love Marianne. Meanwhile, Adrien and Kagami are about to take a trip to London to attend a royal wedding. Marinette, fearing that they will fall in love, decides to send her own love letter to Adrien. However, she mixed up the three letters and delivers the prescription to Adrien, Adrien's letter to Marianne, and Marianne's letter to the pharmacy. Marianne misreads Adrien's letter and becomes convinced that Fu has stopped caring about her. Hawk Moth turns her into "Backwarder", a villain who can turn back her victims' personal timestreams, and learns that she knows who the Guardian of the Miraculouses is. After defeating her, Ladybug delivers Marianne the correct letter. Fu and Marianne reunite briefly, but they cannot remain together until Hawk Moth is defeated.
