Miss Audrey ruled Snowpiercer’s Nightcar, which Mr. Wilford originally intended to be a den of sin and pleasure. But Miss Audrey did something different and necessary with the Nightcar; while it’s still a cabaret and a nexus for the classes of the train’s delights, Audrey recognized that, like her, every passenger aboard was grieving the end of the world. Miss Audrey turned the Nightcar’s private chamber into a place where an entrant could plumb the depths of their trauma and heal themselves of their guilt and burdens – as Miss Audrey showed Melanie, who mourned leaving her daughter Alexandra (Rowan Blanchard) behind, in Snowpiercer season 1.
For Kevin, Miss Audrey’s reclamation of his loyalty to Wilford was extreme: She psychically brought him back into Wilford’s bathtub (a place Audrey herself knows well) and had him face what he did for Wilford’s love. The key to Wilford’s mind, body, and soul control over Kevin is that McMahon believed no one could ever love him as Wilford can. Wilford causing Kevin to self-harm broke his devotion, but this is something Audrey herself had to cope with when the same thing happened to her years before. Using her methods in the Nightcar, Miss Audrey broke Kevin down emotionally and rebuilt him – but she also reprogrammed him to be loyal to Mr. Wilford like a dog would be. It’s a disturbing level of submission that Audrey proved when Kevin unquestioningly complied with her order to lick Wilford’s slipper.
Crucially, Miss Audrey not only rebooted Kevin but she did the same to herself as well. Surrendering to the “pull” she felt from Wilford, Audrey reaffirmed her own loyalty to him – the same applies to her “fixing” of Kevin. The difference is that Kevin can only be a sycophantic tool that Wilford can discard at will. Miss Audrey is something more to Wilford, but she had to confront and stamp out her own doubts to take her place at his side heart and soul. By the end of Snowpiercer episode 7, Mr. Wilford has put his twisted new family in place and is ready to take back the entire train.
Originally from https://screenrant.com/snowpiercer-audrey-kevin-night-car-wilford-fix-explain/