Dark World (2010)

In Russia, the mystic student of linguistic Marina Leonova is in love with her boyfriend Artur. However, he blows her off and dates their schoolmate Vika. When their class travels to the countryside with their Professor Sergey Rudolfovich to research mystic spots, they meet a weird old lady in the forest and she invites them to have a meal with her. The outcast Marina stays by the lake and Artur seeks her to have sex. However they are surprised by their friends and the ashamed Marina runs to the forest. Kostya, who has a crush on Marina, follows her and they get lost in the woods. Marina and Kostya reach an abandoned house and Marina decides to explore the spot. She finds the mummified corpse of a witch holding a shield and she is possessed by a force and faints. Sergey and his students find her and he call a rescue team to help Marina. However, a violent elite squad in a helicopter arrives...