Why?

                                    

                                          
The man slowly opened the door, he locked it tightly behind him, he took the phone from the floor and looked at it and then he began to walk towards Gibbs while glaring at him, he kicked him in the abdomen and punched him in the face "So you think I’m stupid? Well, I’m smarter than you think, I know you did something you shouldn’t have done, and you know exactly who’s gonna be affected by this." said the man with an evil tone "Don't you dare to touch her" shouted Gibbs and tried to stand up, the man took the gun and shot him in the leg, he smiled and laughed slightly "I know you very well, I’ve been watching you for a long time and I’m aware of what you’re capable of doing but you...you don’t know anything about me and trust me, it’s better...anyway your girlfriend will soon be gone, and if you take another wrong step, she'll suffer...and you can't even imagine how much" the man said and smiled. The reason why the man was torturing Gibbs like this was because years earlier, when the man was younger, Gibbs arrested his father that after a few weeks died in prison. After some months his mother, unable to take care of him and his younger brother, left them to his aunt who made them live the worst years of their life. The father deserved that but at the same time the arrest and the death of the father of the two children caused the mother to fall in depression and every time that she looked at her children, she thought about him so, for her, the only solution was to get them away from her. The man now wanted to dump it all on Gibbs holding him guilty of all that, also after years he still couldn't accept what happened, he decided to start all this because a few weeks before the mother had committed suicide and that made him feel the need to take revenge for everything he, his mother and his brother went through during those years. The day after the suicide of the mother, he killed his aunt and that gave him so much satisfaction...after that he decide to find Gibbs and torture him. 
"Why are you doing all this?" Gibbs asked with a really calm tone "You don’t need to know why, you already know everything" the man yelled and kicked Gibbs in the abdomen, he turned around, walked to the door, opened it, went out and slammed it shut.
Gibbs was thinking about Jack but he was also thinking about why he was there, the man didn't explain the reason why he was there...he just said that he knew but Gibbs had no clue about why he was there, he never saw that man before but for now he didn’t care much about why he was there, he was thinking about Jack...and he thought about the call, when Jack told him that he loved him. He missed her, he missed her so much and hoped that all this would end soon, they knew where he was but now the man knew that Gibbs had made that call and most likely this involved the fact that the man could decide to go to another place...what Gibbs didn’t know was that the man didn’t care if they found him or not, he just wanted to torture Gibbs both physically and mentally and that gave him a feeling of satisfaction that nothing else could give him.
By now, Gibbs was just thinking about Jack, when and if he was going to see her again, he thought about how she was, he thought about the kiss and all the pain he was feeling soon disappeared, thinking of Jack was the only thing that was keeping him alive.