Due to a weather problem a plane from Denmark is forced to land at the Slovene airport. Amongst the passengers, being taken to a hotel in Ljubljana, is a quiet, beautiful young Danish girl Iben (25). This is how she meets Tina (25) who drives a shuttle as a summer job. They both need each other, but are very careful because one of them is hiding a secret. They speak to each other in English and in their native languages. Only one of the two languages has the so-called dual, a special grammatical form used in expressions that involve just two subjects. The other language does not. Dual is an honest story about two people who meet precisely at the moment when they absolutely should not have - but they are nevertheless a bit happier because they did.

Fabio has just served eight months in prison for a crime he did not commit, in place of Claudio, a friend of his; former boxer, a delinquent of small caliber that aspires to become the boss of the Mandrione. Claudio manages various trafficking trades and also runs dog fights. Whenever his dogs are injured, he turns to his friend Fabio who, clandestinely in the back room of his dog wash, takes care of small surgical procedures and medications. The friendship between Fabio and Claudio is very ambiguous, almost sick. Claudio has a bipolar personality that sometimes leads him to act with extreme malice in comparison to Fabio that seems to suffer without reacting. All of this lasts a long time, until one day that Fabio, unable to bear it anymore, will decide to carry out his terrible revenge.