Insomnia
Erik Skjoldbjaerg - 1997

A Swedish detective investigating murder in an out-of-the-way part of Norway becomes increasingly unstable as the hell around him merges with the hell inside his head. Neo-noir.

Remade in 2002 with Christopher Nolan directing Al Pacino, Robin Williams, and Hilary Swank. A decent job, but for sheer dark energy, for darkness that nullifies the midnight sun, go to the Skjoldbjaerg.