Odd man out (Tretiy lishniy) (III lishniy) (2007)

A series of unexplained events occur when forty-year old Vera Volina begins dating Sergey, a much younger man, following her divorce. After the family cat is poisoned, some toxic substances go missing from the laboratory where Vera works, and when Vera herself is rushed into hospital after her coffee is drugged, it becomes apparent that someone wants to harm her.
Vera suspects her daughter, Masha, who was last seen near the laboratory on the day the chemicals were stolen, but Masha vehemently denies any involvement. She believes that her paranoid mother may be having some kind of breakdown and a therapist soon confirms her fears. Vera is diagnosed with a split personality stemming from an inferiority complex as a result of Sergey’s age. Vera wants to kill herself, and her subconscious has been responsible for the recent accidents even though Vera herself remembers nothing. A guilty Sergey feels he is to blame, especially when Vera’s condition worsens after she discovers his affair with Masha. Sergey stays with Vera throughout her recovery, but how will he break the news to an infatuated Masha that he has decided to stay with her mother for good?

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Kak pravilo, tretij – vsegda lishnij. No chto delat, esli etot tretij – v tebe samom?
Vere Volinoj za sorok, ona odna vospityvaet pyatnadtsatiletnyuyu doch Mashu. A esche ona vstrechaetsya s Sergeem, kotoryj namnogo molozhe ee.
V dome u Volinyh nachinayut proishodit strannye veschi: s'ev otravlennuyu rybu, pogibaet kot, Vera uznaet, chto iz himlaboratorii ee instituta ukradeny toksichnye veschestva… ZHenschina boitsya, chto kto-to hochet ee smerti. Sergej podsmeivaetsya nad lyubimoj, no Vera okazyvaetsya prava: ona edva ne umiraet, vypiv kofe…s otravoj. Podozreniya padayut na doch. Devushka otritsaet prichastnost k prestupleniyu, no Vera nahodit doma probirku s neizvestnym poroshkom. Masha opyat vse otritsaet, nervy u Volinoj sdayut, i ona obraschaetsya za pomoschyu k psihoanalitiku, a tot predlagaet ej lechenie. Vskore vrach popadaet v avariyu, i Volina vozvraschaetsya domoj. Ej kazhetsya, chto Sergej i Masha - lyubovniki…
Vecherom domoj k Mashe i Sergeyu prihodit sledovatel Gusev, rassledovavshij krazhu himicheskih preparatov. Pogovoriv s Verinym psihoanalitikom, on prishel k vyvodu, chto zhenschina stradaet razdvoeniem lichnosti: iz-za togo, chto Sergej molozhe, u nee voznik kompleks nepolnotsennosti, i podsoznatelno Vera hochet sebya ubit. Vo vseh neschastyah vinovata «temnaya» storona Very, sama zhe ona nichego ne pomnit… Sledovatel, Masha i Sergej pytayutsya predotvratit popytku samoubijstva Volinoj. CHudom im eto udaetsya. Vera i Sergej snova schastlivy vmeste. No v glubine dushi Mashe vse-taki Sergej nravitsya…