Anna

Following top secret experiments, people called "viewers" have developed the psychic ability to enter people's memories. John Washington (Mark Strong), a recent widower, is one such gifted individual. Washington works for Mindscape, the world's top memory detective agency, which offers the abilities of their psychic employees to help solve criminal cases, although their findings aren't yet recognized as evidence in court.

During a session that goes wrong, John suffers a stroke and is left incapacitated for two years. Financially ruined, he still owns the beach house where his wife died, but refuses to sell it. Desperate for money, he asks his old superior, Sebastian (Brian Cox), for a new job. The case is that of a brilliant but troubled 16-year-old girl, Anna Greene (Taissa Farmiga), who is on a hunger strike. Her stepfather wants her sent to a mental institution, which Anna's mother and Anna herself are against. John is sent to end her hunger strike.

John and Anna begin their therapy sessions, focusing on Anna's time at a prestigious girl's school and several incidents that happened there. John finds himself drawn to Anna, while, at the same time wary of her. Anna's nurse, Judith (Indira Varma), whom John has just started dating, is thrown off the staircase, and Anna is blamed. John harbors suspicions towards Anna's stepfather, who he believes has hired a man to shadow him, as well as toward Sebastian, who John learns has withheld a file on Anna from him. Anna's behavior toward John becomes more flirtatious, and she draws a portrait of him with the caption, "You are my only safe place."

John learns that Anna had been involved in a sexual relationship with her photography teacher, Tom Ortega, who took erotic pictures of her. However, when he interviews Ortega, who is now serving time in prison, he insists that Anna was the aggressor and set him up. John and Anna go back to an incident at the school where three of Anna's classmates were poisoned. Anna blames it on another student, nicknamed Mousey. However, when John interviews one of the poisoned girls, she says Mousey does not exist. Anna is able to regain his trust by showing him a photograph of herself and Mousey (Jessica Barden).

John and Anna recover an image of Sebastian approaching her as a four-year-old, which causes John to believe that Anna was sexually molested by Sebastian as a child. Sebastian however vehemently denies this, asking John why he would put him on the case if he had something like that to hide. John informs Anna's parents of his diagnosis and suggests they do not institutionalize their daughter. At home, John discovers that the note on Anna's portrait of him matches one supposedly written by Mousey on the photograph. Going through Anna's yearbook, he sees that the girl from Anna's memories was not nicknamed Mousey. Just then he gets a frantic phone call from Anna.

John races to her home to find that someone has broken in. From the home’s security room, he sees Anna, distraught at discovering the murdered bodies of her parents, fleeing in panic from an unseen assailant. John calls the police but is told that someone else has already called them. He follows Anna into the woods. She tells him she is sorry, and runs away. The police arrest John for supposedly attacking Anna. There is blood on his hands and other evidence which seem to indicate that he broke into the home, drugged her parents, who are revealed to still be alive, then attacked Anna.

After being jailed, John is visited by the man who had been following him. It turns out that this man is another memory detective who has been conducting sessions with John to recover the truth about Anna. The memory detective concludes that Anna manipulated her own memories in order to frame John as her killer. She likely faked her own death in order to escape her parents, who she knew would never stop searching for her if she were alive. John apologizes to Sebastian, who promises to use this new information to secure John's release.

Elsewhere, Anna arranges to have John sent a single red rose, along with a picture of her holding a recent newspaper to show that she is still alive. John, now released from prison, drives to the beach house to find a new family has bought it. He is then able to move on with his life and find peace with Judith.