Joan Cortland
Background
Joan Cortland nee Walsh is a resident of England. Her husband is Peter Cortland. Joan has a friend named Helen.
During the events of Dead of Night (1945) played by Googie Withers
Eliot Foley introduces Walter Craig to the other guests including Mrs. Foley, Joan, Dr. Van Straaten, Hugh Grainger, and Sally O'Hara. As Walter sits down, he at first thinks he is dreaming. He walks up to Dr. Van Straaten and knows he is a psychiatrist, and says he has seen him in his dreams. Dr. Van Straaten thinks Walter must have seen him in the newspapers. Walter continues that everyone in the room has been in his dreams. They think maybe they also saw them in newspapers or around town, but he says that in his dream, they are all together in the same room they are in. He says there is a sixth person that comes in his dream later who he describes. Mrs. Foley and Eliot tell him that they believe him as does everyone else except for Dr. Van Straaten. Hugh then starts his story on the supernatural.
Hugh tells the others that if he hadn't seen the Hearse Driver, he would have gotten on the bus. Dr. Van Straaten suggests that Hugh was still struggling with the psychological stress from his crash, which made him reluctant to go inside any vehicle. Joyce Grainger arrives at the house ans asks Hugh to pay her cab fair as she doesn't have any money. Dr. Van Straaten still doesn't believe and when Walter sees him tapping his glasses, he remembers that in his dreams, Dr. Van Straaten breaks his glasses and then the room goes dark, Eliot mentions the death of a man and then his dream turns into a nightmare. Sally is the next to tell her story of strange occurrence.
Dr. Van Straaten doesn't believe Sally's story and Joyce tells everyone that when she was a nurse there were times when unexplained things happened. Walter says that things in his dreams sometimes change and that in one instance he hit Sally, but not this time as she will be leaving soon. Mrs. O'Hara arrives at the house and takes her away to go to her godfather Edwin's birthday party. Joan is next to tell her story.
On Peter's birthday, Joan comes home with a mirror for Peter's birthday. Peter hangs the mirror up and Joan tells him that she got a ride with Guy. At dinner, Joan notices that Peter seems broody. He tells her about what he saw in the reflection in the mirror, that the background had changed. During the next few weeks, Joan and Peter spent the time looking for a house in Chelsea. Peter eventually tells Joan that the mirror keeps on showing him the other room for longer periods of time and he is worried that the other room in the room is trying to claim him which is evil. He offers to postpone the wedding. Joan walks with Peter to the mirror and has him look in the mirror and he tells her that at this point, he can't even see her in the mirror. She forces him to look into it while holding his hand and the mirror image returns to normal. Time passe and Peter is able to look at the mirror again. While out with her mother, Joan goes to speak with the Antique Dealer who sold her the mirror. The Antique Dealer tells her that the mirror belonged to a Mr. Francis Etherington who died in Marsden-Lacey in 1836. He married an heiress named Mrs. Perry who he eventually murdered and then slit his own throat. Joan goes home to find Peter staring into the mirror. He accuses her of cheating on him and she tries to tell him that the mirror is causing him to act the way he is. He starts to strangle her and Joan uses a candlestick to break the mirror, freeing Peter from its effects.
Dr. Van Straaten tells the others that Joan's story is a case of cryptomnesia, the transmissibility of an illusion by one person to another. Walter tells Dr. Van Straaten that he thinks his dream was a warning and he wants to leave. Dr. Van Straaten stops him and asks him to stay. Walter tells Eliot that he is leaving and Eliot tells him a story that happened to some friends of his.
Everyone laughs at Eliot's story. Dr. Van Straaten reminds Walter that the horror soon starts after Eliot mentions a man died, which must be Larry Potter. Mrs. Foley and Joyce go to make dinner and Dr. Van Straaten tells his story.
Dr. Van Straaten ends his story and tells them that Maxwell Frere is a case of dual identity. As Hugh is handing Dr. Van Straaten a drink, he breaks Van Straaten's glasses. The light's go out and Eliot says George is dying on them. Hugh tells Walter that George is Eliot's power plant. Walter asks to be left alone with Dr. Van Straaten and the the others leave.