Since the beginning of time, there have been "Others" - humans endowed with supernatural abilities - and for just as long, the Others have been divided between the forces of Light and Dark. In Medieval times, the armies of both sides met by chance, and a great battle began. Seeing that neither side had a clear advantage, the two faction leaders, Geser and Zavulon, called a truce and each side commissioned a quasi-police force to ensure it was kept; the Light side's force was called The Night Watch.
In modern-day Moscow, Anton Gorodetsky (Russian: Антон Городецкий) visits a witch named Daria and asks her to cast a spell to return his wife to him, agreeing that she should miscarry her illegitimate child as part of it. Just as the spell is about to be completed, two figures burst in and restrain Daria, preventing her from completing the spell. When they notice that Anton is able to see them, they realize that he is also an Other.
Twelve years later, Anton has enlisted in the Night Watch. While policing Moscow, he encounters several portents that Geser says are linked to an ancient prophecy of an immensely powerful Other that will end the stalemate between Light and Dark, but will be more likely to join the Dark. Anton's investigations lead him to a nurse, Svetlana, whom disaster seems to follow everywhere, and a young boy named Yegor.
In the film's climax, Anton prevents a catastrophic storm from leveling Moscow, when he realizes that Svetlana is an Other, and begins teaching her to control her power. But in the process, Anton realizes that Yegor is his own son, and that his wife was pregnant with him when Anton tried to have a spell cast on her (believing, mistakenly, that the father of the child was his wife's lover, not himself). Learning that his own father tried to kill him before he was born turns Yegor - the Other of the prophecy - against Anton and towards Zavulon, which was the latter's plan all along. In helpless rage, Anton strikes Zavulon, while saying in voice over that, although the prophecy has come true and the Dark's victory seems inevitable, he will not give up.
Konstantin Khabensky as Anton Gorodetsky
Vladimir Menshov as Geser
Viktor Verzhbitsky as Zavulon
Maria Poroshina as Svetlana
Galina Tyunina as Olga
Dmitry Martynov as Yegor
Aleksei Chadov as Kostya Saushkin
Yuriy "Gosha" Kutsenko as Ignat
Rimma Markova as Daria Shultz
Maria Mironova as Yegor's mother
Valeri Zolotukhin as Gennady Saushkin, Kostya's father
Zhanna Friske as Alicia Donnikova
Nikolay Olyalin as inquisitor Maksim
Ilya Lagutenko as Andrei
Aleksei Maklakov as Semyon
Aleksander Samoilenko as Ilya
Anna Slyu as Katya
Anna Dubrovskaya as Larisa
Sergei Prikhodko as Pyotr
Georgiy Dronov as Tolik
Igor Savochkin as Maksim Ivanovich
Nurzhuman Ikhtymbaev as Zoar
Kirill Kleimyonov as himself
loosely based on the 1998 novel The Night Watch by Sergei Lukyanenko
followed by the 2006 sequel, Day Watch.