Ronald Niedermann is one of Alexander Zalachenko's underlings. He is also his son and Lisbeth Salander's half-brother. He suffers from a bizarre medical condition called "congenital analgesia," which leaves him unable to feel pain. Plus, he has superhuman physical strength and particularly hard limbs, lethal weapons unto themselves. As Salander points out, Zala has trained his son to be a killer. However, Niedermann is also prone to hallucinations and is afraid of the dark.
Niedermann is described by Larsson as being over 2 meters tall with a muscular build. He is also said to be blond haired. In contrast to his physical size he has a high pitched voice and a "weak face", both attributes which are likely to stem from genetic abnormality. He suffers from a rare disease, which makes him unable to feel pain.
The Girl Who Played with Fire
Niedermann was sent by his father to assassinate Nils Bjurman, after the lawyer started a revenge plot against Lisbeth Salander. After executing Bjurman and taking his gun, Ronald then intercepted a call from Dag Svensson, a journalist who was investigating Zalachenko's link to illegal prostitution. Niedermann then went to Svensson's house, murdering both Dag and his girlfriend. As witnesses started to gather at the scene of the murder, Ronald tossed away his weapon and escaped from the building.
As the murders were investigated, Salander's fingerprints were found on the weapon and she became the primary focus of the investigation. Ronald was later sent to kidnap Miriam Wu, and he took her to Svavelsjo Motorcycle Club headquarters and questioned her on Salander's location. However Paolo Roberto had tailed him, and after a lengthy fight Niedermann fled the scene with many injuries.
Later Niedermann was with Zalachenko when Salander arrived. Ronald captured her, and as she tried to escape Zala shot her in the head and Ronald buried her. However Salander survived, dug her way out of the hole and came back to the house. Niedermann saw her, bloody and covered in mud, and fled thinking she was a demon. He then ran into Mikael Blomkvist on the road, who tied him to a street sign.
The Girl Who Kicked the Hornets' Nest
Two policeman sent to apprehend Niedermann were killed by him, and he escaped. He went to live at an old factory, where he layed low until Lisbeth turned up. He locked her in and tried to kill her, but she avoided him and nailed his feet to the floor. Salander then called one of the bikers, who turned up and killed Niedermann.