|“||What if I asked you to do something that could profoundly affect an individual on this train?||„|
Joanna is the main antagonist from the 2018 thriller film The Commuter.
Joanna was partially shown following Michael MacCauley (the film's protagonist) on a commuter train; with her presence noted by Michael's friend and fellow rider, Walt. After Michael takes his seat, Joanna joins him and starts what appeared to be a friendly conversation, which later turned into Joanna giving a "hypothetical" scenario. She stated that someone on the train doesn't belong and is headed to Cold Spring, and also revealed that $25,000 was waiting for Michael in one of the washrooms, with a $75,000 bonus if he finds the person. The person, as Joanna described, went by the name Prynne and was carrying a bag, but wouldn't say what was in it. Joanna later leaves the train, but not before revealing her knowledge of Michael's past as a former cop.
Michael finds the $25K in the washroom, proof that Joanna's scenario was literal, and things took a sinister turn when a young woman appeared and handed Michael an envelope, which was revealed to contain a wedding ring belonging to his wife, Karen. After failed attempts to call Karen, as well as his friend and former NYPD partner, Alex Murphy, Michael is contacted by Joanna, who threatened to harm his family if he didn't find Prynne. Realizing the danger he's in, Michael gave Walt a message to call police, but later on, Joanna contacted Michael again and revealed that she had been watching his every move (since the train is rigged with hundreds of hidden cameras and bugs), and that he "broke the rules" by attempting to call police by writing a secret message on Walt's newspaper. She later had her accomplice to locate the man and push Walt into a moving bus, which killed him instantly, and then ordered Michael to place a tracker on Prynne. Michael placed it on a man he believed to be Prynne, only to find the man, named Dylan and an undercover cop, murdered—as he wasn't Prynne.
Joanna informed Michael that police were called due to a reported disturbance on the train, while also stating that Prynne is a witness to a conspiracy, and that she works for a secret organization of corrupt but very powerful people who would do anything to protect themselves. By the film's climax, Michael found Prynne, who was a young woman named Sofia. Sofia stated that she witnessed a pair of men killing city planner Enrique Mendez, who was also Sofia's cousin. She couldn't call police because it was rogue policemen who killed Enrique, who also had evidence of corruption among police and other city employees, which Sofia took. Joanna called Michael again and demanded that he kill Prynne, only for Michael to refuse. The callous villainess blasted Michael for (in her mind) ignoring his family's safety to protect Prynne, and now stated that everyone on the train would have to die. She remotely detonates rigged explosives on the brakes to derail the train, and burned the engineer to death.
Michael and Sam (a conductor) un-couple the carriage from the rest of the train, saving Michael and the others, but Sam was killed (as he was on another carriage that crashed). Later, Mike's colleague friend Murphy boarded the train wreck to talk to him when a police force surrounded and secured the area. However he inadvertedly reveals himself as the rogue cop who killed Enrique, when he used a phrase about "being noble" - which mached the same words clearly heard by Sofia. Michael forces Murph to reveal his involvement in the conspiracy, who later recieves a secret call from Joanna, instructing him to assassinate Sofia. A brutal fight between him, Michael, and the passengers finally ends with the snipers shooting and killing the accomplice, and thus everyone is saved.
Michael was informed that Joanna's whereabouts were unknown, but at the end of the film, Michael found Joanna on a train to Chicago. Joanna claimed not to know him, but Michael uncovered that Joanna was the true mastermind and that she was using Murphy as a pawn as part of her scheme, while also revealing that he's back on the NYPD. The film ends with the implication that Michael took Joanna to custody.