Kvadraturen is an Oslo district where the novel’s criminal and investigative strands converge. A girl’s death there, Sonny Lofthus’s confession, Simon Kefas’s later search for him, and evidence of the Twin’s ties to money laundering all make the neighborhood more than a backdrop: it is a place where hidden transactions, public institutions, and crowded everyday life overlap.

Setting and the buried case

Twelve years before Simon revisits the case, a girl was found dead in a backyard in Kvadraturen. Simon brings a photograph of her to Iver Iversen Senior and recalls that Sonny Lofthus confessed to killing her. The exchange makes the district the location of a past crime whose apparent resolution has become part of the machinery concealing the real perpetrators.

The case belongs to a larger history of suspected police corruption. Simon recalls rumors of a police mole leaking information to the person who controlled much of Oslo’s drug and sex-trafficking activity, but says that no evidence was produced at the time to prove either figure existed. He identifies the crime boss as the Twin. The gap between rumor and proof shapes the district’s significance: Kvadraturen holds the trace of a crime, while the network behind it has long depended on remaining unseen.

Business and criminal networks

Kvadraturen’s associations extend from street-level crime to commercial arrangements. When a prospective client proposes payment in cash and heroin delivered by sea, Nestor considers contacting Iversen. The intermediary insists that Iversen must not know, emphasizing that discretion is essential to the transaction. This exchange places the district’s business world within a wider network of drug supply and concealment, although the scene does not establish that the proposed deal itself takes place in Kvadraturen.

Simon later accuses Iver Iversen of doing business with the Twin through Iversen Property. He says the company helped launder money from drugs and trafficking and received fictitious tax losses worth hundreds of millions of kroner in return. Iversen denies knowing the Twin, but Simon says he has evidence of their collaboration. The accusation gives the earlier rumors an institutional and financial dimension: the concealed network is not simply a single criminal operation, but one that Simon says reached into property dealings and the laundering of proceeds.

The search for Sonny

Years later, Simon goes to Kvadraturen after a police phone-assistance service locates the mobile Sonny used to text him. The phone is a pay-as-you-go handset registered to Helge Sørensen, the same prison officer whose identity card Sonny had used earlier. That detail links Sonny’s movements to the methods of concealment available to him, while leaving Simon with only a small search area and no immediate sighting of his target.

The search is difficult because Kvadraturen is densely populated. Simon studies a map and realizes that the phone’s coordinates cover only a few streets, but those streets contain shops, offices, hotels, and flats. While he waits in his car, a woman mistakes him for a customer because he is alone in a parked vehicle in the city’s busiest red-light district. The moment briefly turns the investigator into someone read through the neighborhood’s ordinary street economy; it also gives him a possible clue to where Sonny might be staying.

Cash, hotels, and inference

Kari Adel develops that clue into a practical search strategy. Sonny has no bank account, credit card, or registered address, but Simon knows he has enough cash, from the Kalle Farrisen murder, to pay for a hotel. Kari estimates that of the roughly 20,000 people staying in Oslo hotels each night, only about 600 pay cash. Simon asks how many of those guests are in Kvadraturen, and she gives him a list of hotels with cash-paying guests.

The list narrows the field without settling the question. Simon scans the addresses and notices that several cheap hotels have cash-paying guests, while some of the cheapest establishments may not even appear on the list. He connects Kari’s information to the woman who approached his car and to the Bismarck Hotel, which he recognizes as the hotel of choice for prostitutes and which lies in the middle of Kvadraturen. The inference redirects his attention from the broad set of hotels toward a particular kind of inexpensive lodging, but the evidence here establishes a lead, not a confirmed discovery of Sonny.

Narrative significance

Kvadraturen gathers separate forms of concealment into one urban space. The old murder gives the district a connection to Sonny’s wrongful or manipulated confession; the allegations against Iversen expose the financial reach Simon attributes to the Twin; and the hotel search shows how a missing person can become legible through small practical signs such as cash payments, a registered phone, and an address list.

The district’s density works both for and against the investigation. Shops, offices, hotels, and flats multiply possible hiding places, while the concentration of cash-paying guests and cheap accommodation offers Simon a way to narrow them. Kvadraturen thus functions as both a setting of anonymity and an investigative map: its crowded ordinary life helps conceal the criminal network, yet the same patterns of commerce and movement give the investigators evidence to follow.