To this day, McGee can't remember why Abby was in the bullpen when Ziva's head was delivered to them in a box. He supposes it doesn't matter, really, not now.
He doesn't really remember much of that day, of the package that arrived on Ziva's (former) desk, so inconspicuous and innocent. What he does remember gives him nightmares.
He remembers Tony, eager Tony, ripping open the brown paper, thinking it was something from Ziva. A sign that she was coming back to them, that all was forgiven. He remembers Tony's puzzled look as a blue cooler is revealed, his bewilderment as he lifts the lid. He remembers Tony recoiling in horror and stumbling back. Tony, sliding down in front of his desk as his legs gave way. Tony putting his head in his hands and gasping for air, the sound reminding Tim of the final, struggling breathes of the dying.
He remembers leaning forward to look in the cooler and seeing Ziva's head and her lifeless eyes, the flecks of blood in her hair. He remembers lurching backwards. He remembers throwing up in the trashcan by Gibbs' desk. He remembers panting and closing his eyes, trying to breathe.
He remembers muttering a feeble warning as Abby steps forward. He remembers hearing her screaming and wishing she would stop, but she doesn't and she screams and screams and he can't breathe.
He remembers Gibbs running into the bullpen, gun drawn, ready for a fight. But there is nothing to fight and he looks in the box and McGee remembers seeing surprise and grief and pain in his eyes (so much pain). Then there is anger and McGee has never been more scared of his boss then it that moment, as he runs up the steps to the director's office, his labored breath moving in time with the pounding of his feet.
He remembers Gibbs dragging Vance down the steps as agents gaped and shouted. He remembers Gibbs stopping in front of the cooler and screaming at Vance to look and see. He remembers more screaming and anger and rage and Vance breathing, hot and heavy as if he has just run a marathon.
And finally, McGee remembers shock as he watches Gibbs shove his badge and gun at Leon. He remembers Gibbs walking away, not looking back. Not at Abby, whom is no longer screaming, just huddled on the floor, sobbing. Not at Tony, who hasn't moved, whose whole frame is shaking. Not at him, who doesn't know what to do.
What he remembers doesn't matter, because everything is broken and torn apart and raw and he still can't breathe.
And he never writes another book. He can't bear to give Tommy and Lisa a happy ending, when Tony and Ziva never got theirs.
Gibbs goes back to Mexico, to Mike Franks and beer, for good this time because losing another agent (daughter) was too much and he won't (can't) do it anymore. He builds in the sunshine and plays with his goddaughter in the sand. His next boat is named the Ziver and the night he carves the name, tears mix with the bourbon in his glass.
Tony leaves N.C.I.S (home), leaves and never looks back. And then there is only pain, and nothingness, and hurt, and what ifs and never agains and oh god please no. At first he drinks to forget because this is all fault, his fault, his fault (because he loved her) and he just wants to be numb. To make it stop, anything to make it stop. Then he drinks to remember, because he has started to forget. Her voice, her smile and when he thinks about how he will never see those things again the pain is crippling and he can't move, can't breathe and god no no no no. And he wants to stop being here, being him, being. He drinks and drinks and ignores his friends. Ignores the knock, knock, knocking on his door. Ignores Abby's shouts and cries and tearful pleas. Ignores McGee's logical appeals and eventually his angry yells. Ignores Ducky's gentle voice and the pity he hears in it. Then he wraps his beloved Mustang around a pole and everything is quiet.
Abby leaves too, takes a job with a fancy forensics lab, somewhere that is nothing like N.C.I.S. That's all that matters really, that it's not there (home). She tells McGee she can't stand to be with all the ghosts. It hurts too much and there is not enough to keep her there anymore, not when there is so much emptiness. And McGee wants to tell her that he should be enough, he should be enough to make her stay. But he doesn't and she goes. Their lunches become awkward and strained and not right and he calls less and less and she stops picking up when he does. He sees her next at Tony's funeral and she is a stranger.
And then McGee is alone again (he will be always alone). He stays at N.C.I.S, he is there when Ducky retires and for Jimmy's first (and thankfully last) meltdown as M.E. He cannot leave; someone has to stay, to remember. To remember what they were, remember that they were more then names or photographs on the wall of the fallen, remember that they were there. People come and go, but it is never the same, and he cannot stop the feelings of anger and grief when he sees someone else at their desks. These people don't understand that they are sitting next to ghosts, and he will never be able to tell them. Besides, he thinks might be turning into one too.