The czar of Russia has died and a power vacuum has developed. This period in the late 16th and early 17th century has been called "The Time of Troubles." There are many impostors who claim to the right to rule, but there's only one heir, the Czarina Kseniya Godunova. She has married a Polish military leader who wants to claim the Russian throne in her name so he can rule all of Russia. As the Poles move in on Moscow in an attempt to install the czarina on the throne, Andrei, a serf with a life-long infatuation of the czarina attempts to save her from her brutal Polish husband.
The film begins in the 1980s Soviet Union. Two best friends, Orlov and Muravyev, are serving at the Black Sea Navy Base in Sevastopol, Crimea. Both fall in love with one beautiful girl Nelly, and their friendship suffers a first blow. Because she picks Muravyev, his friend Orlov struggles with an inferiority complex and becomes a secretive alcoholic. After the collapse of the Soviet Union in 1991, both friends are transferred to the Northern Fleet on the Polar Ocean. One day their sub is performing a routine training. A disturbed WWII mine slowly moves on a collision course with the sub. A mighty blast knocks down everyone inside the wrecked sub, 72 meters below the sea level. Then ensues a nerve-racking struggle for survival.
Sergei and Andrei are walking through a city park and see that a film shoot set just post World War II is taking place . They climb over the park fence to get a better view but hit some cable lying on the ground and find themselves in the past - on May 8, 1949, a day which they seem doomed to relive over and over again.
