The Girl Who Takes an Eye for an Eye by David Lagercrantz (2017)

I don't know why Lizabeth Salendar and Michael Blomquist are such appealing characters, but they are and though they too are fighting some incredible evil, it never gets as dark as in some of the other Scandinavian authored books. I thought Lagercrantz was only going to follow Steig Larrson's series for one more books, which is why I was happy to see this.

Salendar is in jail from the last adventure - not for long, but still. The resident bully can't quite figure her out, but does make life miserable for a young Muslim woman, who is in for killing her brother. Salander steps in and chaos ensues. 

Blomquist spends time researching Leo ??? per Salendar's request and finds the remnants of a scientific experiment on twins turned evil and some of those responsible for Lizabeth's life traumas. The author references the Minnesota twin studies just to give this a sense of possibility. Blomquist speaks with enough of the players from the experiment to start getting the picture and one of the players is bent on eliminating anyone who would shed light on the past.