If you enjoyed the Millenium trilogy and Swedish detective writers in general, then you’ll love The Savage Altar by Asa Larsson. This is the first in the Rebecka Martinsson series so as good a place as any to start.
Set in the frozen north of Sweden, Rebecka comes to help her friend who is accused of murder. The brother happens to be a charismatic leader in the church called The Source of All Our Strength, a large evangelical and wealthy mega-church. Rebecka, now a corporate lawyer, is reluctant to go back to the place of her childhood which holds so many bad memories for her. And the townspeople, especially the church leaders, are not too happy to see her either.
The authors writes beautifully and the plot twists and turns and keeps you interested all the way through. I did find the ending a little abrupt and could have done with a bit more explanation but it may be in the next book in the series.
If you like Swedish whodunnits, then you will certainly enjoy this one. Recommended.