Need help finding a drama...

I remember the first episode was about some kind of blackmail somes higher up received by phone... and one of the main character (i think he was one of the MC) was a special force member... and hes "dad" got kidnapped and while saving him the dad did a nod i think to tell the son to shoot... and then there was an issue with hes brother i think who was kinda mad he took a shot while the dad was being held hostage