NEW BOOK SERIES 2026
I am Tuomas Niskakangas, an author and a journalist. In Germany I go by my first name and middle name Tuomas Oskari.
My new thriller series Department K will begin in 2026 with the release of first two books of the series. After working on the series for two years I can't wait to see the first books in stores.
My first three books were part of Leo Koski -series: Roihu (2021), Miekka (2022) and Kotka (2024). My goal is always the same. I want to provide my readers
with an engaging experience that leaves
you feeling fully entertained, and yet not dumber.
NEW BOOK, MAY 2026
SULJETTU KANSIO (The Sealed Case)
Department K
The start of a gripping new thriller series! The Department K series blends a web of power games and criminal investigations with finely crafted psychological portraits.
When journalist Joel Saarni's affair with his editor-in-chief makes the tabloid front page, he's forced to leave his job. But the unfinished story won't let him go. Someone has sent him a folder containing highly incriminating material: a Finnish network equipment company appears to have made illegal deals in Russia. But why?
Corporate lawyer Petra Thorry has her own reasons for getting involved. She's obsessed with solving the mystery of a child who vanished in the 1990s.
As the investigation deepens, Petra and Joel are drawn into a tightening web of lies and espionage—where the deadly strings are pulled by Department K.
The Sealed Case launches a new top-tier Finnish thriller series. Department K is an addictive story about unchecked power—and the people who can no longer look away.