In the past Alie has recommended some really great mysteries: In the Woods by Tana French, The Girl with the Dragon Tattoo by Stieg Larsson (which is a total suck-you-in and spit-you-out thrill ride that you want to immediately line up for again), Finding Nouf by Zoe Ferraris (we just got this in paperback today! I can also vouch for this as a really great read.) and Field of Blood by Denise Mina.**
Her new recommendation is for K. O. Dahl's The Fourth Man: "Yet another engrossing and captivating Norwegian mystery. There are so many available in English now--but this one stands out. A wonderful mystery and interesting characters."
**You can read all her recommendations here!