It's not the danger... it's the fun

Gibbs: “Door is unlocked, Abbs.”
Abby: “Hi, Gibbs.”
Gibbs: “So? You see the guy?”
Abby: “Kyle? My brother? … Yeah.”
Gibbs: “… How’d it go?”
Abby: “It was fine… I didn’t tell him who I was. He seems really, really nice. He doesn’t need the added stress. I mean, he just got chosen to donate a kidney, and the operation’s tomorrow. I just… I have things I have to… work out, you know? … Are you drinking tea?”
Gibbs: “Yeah. Don’t tell Ducky. He’ll give me a lecture on brewing … What do you need to work out, Abbs?”
Abby: “Just… this whole brother-sister thing. It didn’t make any sense to me. I mean, Kyle and me… our DNA is a total match. So, we have to have the same biological parents. So then I was like… “What, did they give him up for adoption?” And I-I can’t imagine the wonderful, loving parents that raised me and Luca ever giving up a child… But they would have adopted a child… And they did … Me … I’m adopted, Gibbs.”
Gibbs: “… How do you know that?”
Abby: [opens her necklace] “This is my mom’s hair. And I-I ran a DNA test on it and I compared it… to mine. It wasn’t a biological match, Gibbs. So I… I don’t know who I am anymore. I don’t know… who my parents were. I’m just like… like Little Orphan Abby.”
Gibbs: “Abbs… you’re still the same person. Your parents… they’re still your parents, as you remember them… Family’s more than just… DNA. It’s about.. people who care and take care of each other.”
Abby: “I know… But why didn’t they tell me I was adopted? I mean, there’s got to be a reason. And I need to find out before I… completely turn Luca and Kyle’s lives upside down.”
Gibbs: “You don’t have to do this alone, Abby…You’ve got a family. And we’ll help you through it.”

~ 9x04 “Enemy on the Hill”