The film opens with Mladen Pavlović (Nebojša Glogovac), sporting bumps and bruises on his face, nervously smoking a cigarette while talking to unrevealed individual(s).

The movie occasionally returns to the scene of Mladen talking to the unseen individual(s) and discussing different details following key plot points or displaying inner torment over the unfolding story.

Mladen is a young professional residing in Belgrade where he works as construction engineer in a decrepit state-owned company that's undergoing the process of privatization.

He drives a beat-up Renault 4 and rents an apartment with his wife Marija (Nataša Ninković) who teaches English in a primary school.

They arrange and lead a fairly normal and happy family life—cheering Nemanja on at swim meets and taking him to the local playground where Mladen becomes acquainted with their blonde neighbour (Anica Dobra) who also brings her daughter to play there.

After undergoing emergency reanimation, he is diagnosed with a heart muscle condition that requires immediate surgery since the next inflammation that could come at any time might be fatal.

They are further informed by Dr. Lukić (Bogdan Diklić), that the procedure is only performed at a clinic in Berlin, Germany, costs €26,000 and is not covered by domestic health insurance plans.

Soon, the family gets a call from a man who claims to be interested in helping Nemanja after seeing the ad, but is not willing to discuss the details over the phone so the meeting with Mladen is arranged the next day at a bar in Belgrade's Hotel Moskva.

At the meeting, the dapper, a well-spoken middle-aged man (played by Miki Manojlović) says he's willing to pay €30,000, explaining that that should cover Nemanja's surgery and three plane tickets to Germany.

Furthermore, he says that all he wants in return is for Mladen to murder someone, seeing him as the perfect candidate to carry out the crime, because he does not have any prior record and because he is an honest, hard-working man whom no one will suspect.

Coming back home, Marija is eager to hear how the meeting went, however Mladen doesn't mention the shocking offer he received, simply dismissing the man he met with as "some nutcase".

Lying in bed that night, tormented, Mladen attempts to get some input and advice from Marija by saying he's got something important to tell her while looking ready to finally clue her in on what's going on.

That morning, Mladen shows up at the bridge and finds the plastic bag containing a loaded handgun, a letter with instructions and a message that promises a cash advance will be in his building mail box the next day.

Using the instructions he's been provided about Ivković's habits, Mladen scopes out his apartment and watches him enter his Toyota Land Cruiser 100 series SUV to go to work in the morning.

Petar's brother (played by Vuk Kostić) gives an emotional and impassioned speech vowing to find the killers and get revenge.

She also lets on that she knows her husband to have been involved in all kinds of dodgy stuff by saying that all of them knew his one side, but adds that he was the love of her life and was wonderful to her and her two daughters.

Tormented by guilt and crushed by the fact he can't collect the rest of the money, he stumbles around the city drunk and gets into a fight with some arrogant youngsters, smashing the windshield of their Mercedes with a large rock.

The next day, when questioned about the incident with the youngsters, he suddenly admits to killing Petar Ivković and tells the inspector (Milorad Mandić) every single detail of how it went down.

Mladen comes home where Marija has had just about enough of his mysterious and days-long disappearances, which she sees as his failure to deal with the situation properly and even abandonment of his family.

After hearing a gypsy speaking on the other end of the phone, Mladen realizes where his antagonist is and rushes into his car and starts following the man's silver BMW.

Underneath its simple noir narrative, some of the movie's key points lie in spotlighting what the author sees to be the staples of post-Milošević Serbian society such as the huge gap between the rich and the poor, an entire nouveau riche class that managed to gain enormous wealth through shady means in the years since the collapse of communism, a middle class that is teetering on the edge of poverty, patriotism being used to cover up criminal activities, workers and clerks at the mercy of ruthless foreign-based businesses that negotiated their entry into the shattered Serbian economy from an overwhelming position of strength, etc.

[7] In April 2008, Hollywood production company Alcon Entertainment closely affiliated with Warner Bros. bought an option to remake the movie within 18 months of the purchase.

[8] Finally, in early November 2008, it was announced that after buying the rights to Klopka, Alcon Entertainment gave a green light for the remake to be directed by Ericson Core based on an adapted screenplay yet to be written by Matthew Aldrich.