The following version of this book was used to create the guide: Alsterdal, Tove. We Know You Remember. HarperCollins, 2021.

Tove Alsterdal's crime thriller novel We Know You Remember is written from the third person point of view and employs both the past and present tenses. Although the novel toys with conventional notions of novelistic form, the following summary embraces a linear mode of explanation and the present tense.

When Olof Hagström returns home to Kungsgärden to visit his father, Sven, he is shocked to discover Sven dead in the bathtub. Because Olof was implicated in the rape and murder of a teenage girl named Lina Stavred 23 years prior, he flees his father's house. A neighbor apprehends him on the street, demanding to know what he is doing. Olof says Sven is dead and the neighbor immediately calls the police.

Thirty-two-year-old investigator Eira Sjödin responds to a call about Sven's suspicious death. She immediately believes that Olof is to blame, as she is familiar with his criminal history. She informs her colleague of Olof's past. However, the more she inspects the murder scene and learns about the circumstances of Sven's passing, the less certain she is that Olof is guilty.

The police soon begin interviewing Sven's neighbors, Tryggve and Mejan Nydalen. The couple insists that they had no interaction with Sven. However, the cops later learn that Sven may have known about Tryggve's criminal past. When Tryggve was a young man, he served time for his involvement in the gang rape of a teenage girl named Anette. Disgusted by his own son's crime, when Sven learned what Tryggve had done, he confronted him. Mejan worried that Sven would out her husband and ruin hers and her family's idyllic life. Without her family's knowledge, she murdered Sven with a hunting knife while he was showering.

Mejan eventually confesses to the crime and is imprisoned. Eira and her colleagues interview Tryggve after his release and his wife's conviction. During the interview Tryggve offers them a new tip about Lina's disappearance 23 years earlier. He says that he saw her on the night of her disappearance in a rowboat with another individual. Curious to know the truth, Eira begins investigating further. However, the more she studies the archives from Olof's case, the more disturbing information she uncovers. She realizes that her brother, Mangus, and his best friend, Ricken, may have been involved.

In an attempt to prove her brother's innocence, Eira speaks to her mother's best friend, Unni, to Olof's sister, Ingela, and to Lina's former friend, Elvira. Each of these conversations confirms her worst fears: that Mangus may have killed Lina. Meanwhile, Eira's colleagues discover a set of bones near the river belonging to a young boy named Kenneth. They soon learn that Lina planned on running away with Kenneth. Because Mangus was heartbroken over his breakup with Lina, he was jealous when he found out her plans. He followed the young lovers into the woods, where he found them engaged in a sexual encounter which he mistook for rape. He attacked Kenneth, who fought back. Before Kenneth could strangle Mangus to death, Lina killed Kenneth with a metal rod. In order to repay her for saving him, Mangus offered to bury Kenneth's body. He then told Lina to take his motorbike and flee.

Eira learns that Lina is still alive and living not far away. Although Mangus confesses to the murder of Kenneth, Eira wants him to tell the police the truth. Mangus tells his sister that he must serve the time because of his involvement in Kenneth's death. He also has little interest in dragging Lina back into the past and stealing her freedom from her.