The movie starts out with a man (pictured bellow) being interrogated. His name is is Vincent and he is played by Karl Urban. Vincent is an architect that recently had a grand opening of his new building and he invited his closest friends along with other colleagues and such. (Pictured below from left to right are the 5 friends. Vincent, Chris, Luc, Maxim, and Filip)
So, Vincent tells his friends that they can all share a room (The Loft) where they can get away from their wives and just have fun without anything tracing back to them.
As of right now, we have absolutely no idea why the men are being interrogated. I mean when you get 5 mischievous men, a room they share, and the cops, you can only conclude that someone either stole something, broke something, got caught with drugs, or there is a dead body.
If you thought someone died then you're right. If you thought there were drugs involved then you were also right. Now, the problem is that no one knows who did it (apparently).
From the movies and shows that I have seen, I know that someone was framed or someone was too drugged up to know what happened. Throughout the movie, you begin to notice little things that each character does. For example, Filip is what you would call a "hot-head". You say one bad thing and all of a sudden the Hulk is in your room. Maxim is the drunk; he cannot keep his mouth shut for the life of him. There's a scene where he almost tells all of the wives that the 5 of them are sharing the loft to cheat on them. Which leads to Luc tipping his chair over and knocking him down. Speaking of Luc, he's what you'd call an observer. Throughout the movie he never sleeps with any other woman and he always stays in the background while his friends are either making out with their new girlfriend or butt naked in a pool. Vincent is the leader. I mean, he is the one who brought up the loft, he's the one who sleeps with the most girls, and he's the one with the most money. Now, as everyone knows, there's always a romantic. Chris is the one who just stands by his friends until he meets a girl named Ann who ends up showing up at almost every event Chris attends with his friends because she works for a councilman. Chris only ever sleeps with her countless times and he tells her he is falling in love with her but then she goes on to tell him that he doesn't "know the half of it".
Now, this is where it gets interesting. In the beginning, the first person to walk in is Luc. He drops the grocery's he bought, on the floor, and then calls everyone EXCEPT Vincent. Everyone except Chris had their room key which means he must have left it somewhere. When the other 3 ask why Vincent wasn't called, Luc shows them the videos he has been recording since the first day. Filip nearly chokes him out when he finds out the Luc has basically been spying on everyone but they soon calm down when Luc tells them that Vincent has been lying to them and using them. Vincent had slept with the most important women in their lives: Filip's sister, Chris's fling Ann, Mamix's wife, and , of course, Luc's love interest who is dead on the bed.
Fast forward to the 5 men in the loft and Vincent admits that he was in the loft the night that the girl died but he says she was alive when he left. Chris then breaks a glass cup which signifies that the other 4 could carry out their plan to drug Vincent and frame him for the death. Later on in the movie, the man who is arrested is Filip because he was being messy when he left the evidence all over the room. Not only that, Vincent was not the one who murdered the girl.
So who did it? We know that Vincent did not do it and Filip couldn't have done it because he was the one to frame it all on Vincent. So we are left with Luc, Chris, and Maxim. The mastermind behind it all is Luc. The reason why the girl is dead is because he noticed how badly Vincent treated her and he asks her if she would give him a chance because he would never hurt her but she says no. So when Vincent leaves her in the Loft, Luc goes inside and talks to her. She says she wants to lose feelings for Vincent and by then, Luc drugged her and laid her down in the bed. He then injects insulin into her body so that she dies without feeling a thing. The problem is that Luc didn't give her enough insulin so when Filip slashed her wrists to make it seem like a suicide, she was bleeding out right then and there.
The only two people of the 5 that know about what Luc did are Luc and Chris. It only takes Chris a few hours to realize that Luc was the one who killed her and he wanted to pin it all on Vincent because he took the woman he loved away from her. "He was standing in between us." The movie ends with Luc trying to kill Chris but then Chris turns the knife on Luc and Luc throws himself off the balcony as soon as the cops arrive.