"The Girl in the Spider’s Web" by David Lagercrantz, summary

The detective novel "The Girl in the Spider’s Web" was published in 2015. The book continued the story of the characters Lisbeth Salander and Mikael Blomkvist after the death of their creator. The author was Swedish journalist and writer David Lagercrantz.

The novel is the fourth installment in the Millennium detective series. The first three books — The Girl with the Dragon Tattoo, The Girl Who Played with Fire, and The Girl Who Kicked the Candle — were written by Stieg Larsson. David Lagercrantz later continued the series with The Girl in the Spider’s Web, The Girl Who Followed the Shadows, and The Girl Who Must Die. In 2018, the novel was adapted into a film by director Fede Alvarez, starring Claire Foy.

The Crisis of a Journalist and the Return of a Scientist

Reporter Mikael Blomkvist is going through a difficult period in his career. Millennium magazine is in economic decline, and the Norwegian media holding Serner Media, which acquired a 30 percent stake in the publication, is trying to change its format. Colleagues are openly criticizing Blomkvist, calling his investigative methods outdated.

Professor Frans Balder, an expert in artificial intelligence and quantum computing, arrives in Stockholm from the United States. Having resigned from the IT company Solifon, the scientist decides to take his eight-year-old son, August, away from his ex-wife, Hanna, and her hot-tempered husband, Lasse Westman. The child suffers from autism, does not speak, and appears completely withdrawn.

After settling his son in a villa in Saltsjöbaden, Balder noticed the child’s astonishing savant talent. Augustus reproduces complex three-dimensional objects and mathematical proportions. The professor soon realized that the boy possessed a perfect photographic memory and captured the details of the world like a three-dimensional camera.

Secrets of Cyberspace and a Pub Meeting

At the US National Security Agency headquarters in Fort Meade, IT security director Edwin Needham discovers that spyware has penetrated the internal network. The hack was carried out by Swedish hacker Lisbeth Salander, known online as "The Wasp."

Lisbeth works alongside a hacker nicknamed Plague and representatives of the Hacker Republic. She leads her own hunt for the international criminal group "Spiders," led by a man named Thanos. She discovers that Balder’s unique research in artificial intelligence has been stolen and resold to cybercriminals.

Professor Linus Brandel, a former assistant, meets Blomkvist in a pub. Linus tells Blomkvist about Balder’s panicked fear for his life and the visit of a strange hacker who inspects their computers. Based on the description of her appearance and behavior, Blomkvist recognizes Lisbeth Salander and decides to contact the professor.

The Saltsjöbaden tragedy

SEPO Security Service analyst Gabriella Granet warns Frans Balder of an impending assassination attempt. The scientist refuses to leave his home, but agrees to have an alarm system installed by Milton Security and a police patrol.

That night, Balder summons Blomkvist to his villa, wanting to hand over the materials he has. To protect his work from capture, the professor completely destroys his life’s most important program on his laptop — the artificial intelligence he created, named "August." Before Blomkvist arrives, the hired killer Jan Holzer infiltrates the villa.

The assassin shoots Balder in front of little August. The mercenary decides not to touch the child, believing him mentally retarded and incapable of testifying. Taking the dead scientist’s laptop, Holzer escapes.

The drawing testifies to a crime

Mikael Blomkvist finds Balder’s body and saves the hysterical August. The police arrive on the scene, and the investigation is assigned to the team of Inspector Jan Bublanski and Inspector Sonja Mudig.

The boy is returned to his mother. In the apartment on Torsgatan, August begins drawing incessantly, depicting the checkered bedroom floor, mirrors, and the figure of a man holding a flashlight. Blomkvist finds the crumpled drawing in the trash can and realizes the child has captured the moment of his father’s death.

The journalist contacts Lisbeth Salander. The hacker realizes that her twin sister, Camilla Salander, is behind the Spider syndicate and has taken over part of their father, Alexander Zalachenko’s, criminal empire. Camilla learns of August’s drawings and orders the boy’s assassination.

The ambush at Sveavägen and the rescue of the boy

August is temporarily placed in the Ódin Children’s Center, run by Torkel Linden. The criminals send the director a fake email, purporting to be Professor Charles Edelman, requesting that the child be taken to Sveavägen Street.

Lisbeth Salander uncovers the deception and rushes to the rescue. On Sveavägen Street, Holzer opens fire on Linden and August as they exit the building. The center’s director dies instantly, but Lisbeth shields the boy with her body, receiving a shoulder wound.

Salander hijacks a passing car driven by soccer player Jakob Charro and takes August away. After bandaging the wound with her own jersey, she delivers the child to Gabriella Granet’s isolated dacha on the island of Ingarö.

Skirmish on Ingarö Island

At the dacha, Lisbeth helps August calm down. The child begins writing down complex mathematical equations and factoring integers into prime factors. Then the boy takes some crayons and, with the precision of a portrait artist, draws the face of his father’s killer, complete with a scar on his forehead.

Salander takes a photo of the killer and sends it to Inspector Bublanski. At that moment, Holzer and armed bandits approach the house. Lisbeth engages, fires back, and seriously wounds Holzer, after which she takes August to safety.

The police obtain a photo of August and, using a database, identify the killer as former Soviet special forces soldier Boris Lebedev, who was living under the name Jan Holzer. Mortally wounded, Lebedev dies in the hospital.

Revelation and Finale

Bandits kidnap and torture Andrei Zander, a young Millennium reporter who was trying to protect the editorial secrets. The tragedy shakes Blomkvist, but strengthens his resolve to see the investigation through to the end.

Edwin Needham arrives in Stockholm and passes on classified information to Mikael about abuses of power at the NSA. Lisbeth decrypts the downloaded intelligence files and sends Blomkvist evidence of collusion between NSA officials, senior Solifon executives, and Camilla’s gang.

Mikael publishes a large-scale investigation dedicated to the memory of Andrei Zander. The article resonates worldwide: NSA officials are fired, and Millennium magazine is saved from collapse thanks to increased circulation and anonymous financial assistance from Salander.

August, along with his mother, Hannah, leaves for Germany to study under the tutelage of Professor Edelman. At the end of the novel, Lisbeth Salander arrives at Mikael Blomkvist’s apartment on Bellmansgatan.