To make everything more clear for you, they are a mafia group who are trying to find their target( the head?mafia boss of the other group, you can see it in the first scene where chan was holding the news paper), and as you could see they were making business stuff (when changbin begin to rap his first verse) and when the other man pointed the gun on his temple, there was a scene where the lighter (flew?) In han's sleeve( if you look closely) . Afterwards they were trapped right? Han used the same firelighter he hid in his sleeve and used it to escape with his team .next as you saw, changbin was throwing the green bottle he lightened and threw it at the building, well, if you pay attention to the scenes where the glitch covered the scene(green glitch) it was the backflash of their plan to destroy the building of the other rival group ( and the rivals themselves ofc) . LASTLY the biggest twist in this whole video. At the end of the scene , you could see i.n picking up a gun or his gun and smirking and smiling weirdly right? It turns out, that I.n was the rival boss (of the other group) skz keep looking for, but didn't tell them, that's why they where probably always unsuccessful to catch the rival boss ( i.n) You can see him saying it on the behind the scenes of freeze MV I hope this helped!
