DW: The fourth volume of the "Millennium" series will be released internationally on Thursday (27.08.2015), except in the US, where it will be released on September 1. Stieg Larsson did not complete the book before his death, but it is said that he had already written three-quarters of the manuscript and that David Lagercrantz decided to rewrite it completely. What do you think of new authors continuing or rewriting other people's stories?

Tobias Gohlis: This might be a special feature of crime fiction: It happens quite often. There are always new "Conan Doyles," for example - it's most common with the "Sherlock Holmes" series.

Patricia Cornwell wrote the 200th ending to Charles Dickens' last, unfinished novel "The Mystery of Edwin Drood" when she was a student.

In some ways, this is even a sport. For example, with "Satori," the American crime writer Don Winslow wrote a prequel to the Asian adventure novel, "Shibumi," written by an author who's barely known now, Trevanian [Editor's note: the pseudonym of Rodney William Whitaker]. So even important, well-known authors like Don Winslow have used established fictional settings to create new material.

The fact that a new author, David Lagercrantz, wrote the fourth volume of the series doesn't initially reveal anything about its quality. It could turn out to be the first really good book to be published under the Stieg Larsson label, even if it's not by the author himself.

It is even rumored - and the truth will probably never be told - that Stieg Larsson, who was originally a graphic designer, actually only wrote part of the books himself. He might have conceived them without writing them out completely. Some say that his girlfriend, Eva Gabrielsson, who has laid claim to a portion of the royalties, not only typed and edited his work, but brought the novels into a readable form. So we don't even know if Stieg Larsson was the actual author in the first place.

How do you explain the incredible success of Stieg Larsson's "Millennium" trilogy?

There are several explanations, but no one can explain it exactly - I can't either. I'd say, 50 percent of its success has to do with the fact that the books come with a highly interesting background story, which could be called "Stieg Larsson and his heirs," with his early death, etc.

Another 30 percent is based on good marketing, and the last 20 percent of this success has to do with the actual narrative in the novels. And here I'd add that it's not primarily due to the crime story itself, but rather to the new perspective on male-female relations, which probably didn't exist before in such a popular form.

Are you referring to the love story or to the abuse and pedophilia?

I mean this in a more general way. Stieg Larsson might not have been the first one to do so, but he was the first who became successful with a story breaking typical gender representations.

Classic crime literature depicts women in different variations of victims, whores or "femmes fatales." There has rarely - or perhaps never - been such a tough, combative and cool female character like Lisbeth Salander before.

Another unique feature, especially in the films, is that she's such a cold avenger. She is also strong and therefore she serves as a role model to many readers, both female and male.

Salander also deals with two opposing male figures. On the one hand, there is the brutally guilty character of her guardian who raped her as a child, which is so to speak the most evil incarnation of machismo. On the other hand, there is the understanding soft man, Mikael Blomqvist. He is always gentle; he never takes the first steps to kiss a woman.

The actor in the Swedish films depicts him with this unbelievably plain face, never wanting anything, yet women are into him just the same. Not only male readers can identify with these characters, but women can also fantasize about men who don't express their desire openly. This constellation of characters provided an appealing social role model.

Is it unusual for an author to obtain so much success posthumously in this rather trivial genre?

First of all, I would not describe crime fiction as a trivial genre per se. Generally speaking , there are good and bad novels. Yet, serious literary critics don't want to discuss Utta Danella's successful novels - and they don't even want to talk about Stieg Larsson.

There's always a good background story behind such a worldwide success. Take, for example, the US author Patricia Cornwell: She is now worth about $120 to 200 million as an author. She also had a personal story which strongly contributed to her success. She became well known in the US for her lesbian love affair with a married FBI agent, and that was everywhere in the media.

And Stieg Larsson, the anti-fascist who fought against right-wing extremists and who practically died while chain smoking at his desk, isn't a bad story either.

Do you believe that the real-life background of the series, such as the magazine "Expo" which served as the inspiration for the "Millennium" magazine in the novels, also played a role?

I think so. It can't be explained otherwise. My point is that there should always be something that triggers the fascination and the enthusiasm of the readers. Even the Peruvian author Vargas Llosa once said that Stieg Larsson reminded him of Alexandre Dumas, the successful French novelist from the 19th century.

Nevertheless, it's not the literary qualities of these works which attract a broad readership in the first place.

Did you like the films?

I've only seen the Swedish adaptations with Noomi Rapace, not the American films with Rooney Mara and Daniel Craig in the lead roles. I enjoyed them, yes, but they also made me realize for the first time the extent of the crudeness of the novels.

Can you be more specific?

The films were obviously made by professionals and therefore the narrative is a lot smoother and somehow more meaningful than in the novels - they include so many details which are a bunch of rubbish. There are pointless descriptions, confusions in the plots: All this isn't included in the films.

The director Daniel Alfredson and his team knew that they had to rework it well for the cinema. In this respect, I enjoyed the films more than the books - but they didn't get me really excited either.