: This specifies the high-definition resolution and source (Blu-ray disc).
: This means the file contains multiple audio tracks, typically the original Russian and an English dub.
: The film is often described as an ambitious Russian horror movie that draws inspiration from classics like The Thing . While it has been praised for its atmosphere, some critics found the plot muddled and the pacing slow.
: Inspired by the real-life Kola Superdeep Borehole, the story follows a small group of researchers who venture down into the world's deepest borehole to investigate a mysterious outbreak and discover something terrifying hidden deep underground.