Following Monarch's defeat, Marinette feels as if she is drowning in secrets. Unsuccessfully trying to readjust to her ordinary life, she's simply trying to keep her head above water. Constantly living in a state of anxiety, she's pushing away everyone she cares about, including Adrien.
Oblivious to all of this, Adrien believes his dad was a hero. As he struggles to cope with his newfound familial status, or lack thereof, he knows he can count on his one constant; Marinette. However, unfortunately for him, Marinette has never been so distant, so he decides to find solace in her company as Chat Noir.
As they both try to readjust to a normal life, their comfort is shattered at the reveal of a new villain, who seems even more cunning than Monarch. As the new holder of the Butterfly Miraculous, Ladybug and Chat Noir must fall back into the hauntingly familiar and repetitive dance of constant conflict.