"We've known each other for a really long time," I began cautiously.

"You don't have to do this," Mark replied.

"You think I'm a goody-goody."

"Addie, I didn't mean to hurt your feelings when I said that."

"No, it's mostly true."

"Mostly?"

"You'll see."

"What or who did you do?"

"Mark!" I gave him my best scare-the-interns glare. "How many siblings do I have?"

"Two. Your older brother and your younger sister. Josh and Kaci."

"How many nieces and nephews?"

I watched Mark's face for any sort of reaction, stalling for time. I knew I could trust him with this information, but giving it out after swearing never to talk about it again was harder than I thought. He pulled back from me and looked deep into my eyes then kissed me gently on the tip of my nose.

"Three. Josh has two daughters and a son."

"I used to have another nephew."

"Used to?"

"He..." I choked back tears, "He…died the first year of my neonatal fellowship."

"Huh?"

"Kaci accidentally got pregnant. She had been seeing this guy for a few months, but he disappeared as soon as she told him about the baby."

"What happened to…your nephew?"

"Kaci didn't want anyone to know she was pregnant, especially our dad. You know how strict he was, and still is, with us girls. She was only 16 at the time. So she and my mom decided to go on a long vacation. Dad didn't question it. He was too busy with his practice to miss them anyway. Instead of going somewhere, they moved into the Plaza. Mom paid for everything with one of her dad's credit cards so my dad wouldn't find out where they were." By this point, tears were falling fast.

"It's okay," he tried to brush the tears, but they kept falling. "Am I going to have to kiss away your tears?"

"No. They'll just keep coming."

"So, what happened when it came time for the baby to be born?"

"He had a congenital birth defect that caused him to have a weak heart. His lungs were underdeveloped, and he had a cleft palate."

"He needed surgery, badly, but my stubborn sister wouldn't let anyone except me operate. Even though I was only a first-year fellow, she wouldn't have it any other way. Her reasoning being that I separated conjoined twins the week before. Why couldn't I save his life too? So, I gathered a team with the best cardio staff at Mount Sinai. The head of cardiothoracic surgery stood next to me, telling me every single move to make. The procedure was textbook, but I couldn't save my nephew. He even said he could just barely do a better job. Kaci never blamed me for losing her son, but I've always blamed myself. I should've refused to do the surgery knowing I didn't have the experience."

"No, Addie, you did the right thing. He just couldn't be saved, and that is not your fault."

"So, now you know why I'm so hell bent on saving every patient I get. I never told Derek. I knew he wouldn't approve of me performing surgery on someone so closely related to me."

"You did what you had to do, and you did your best."

"I just wish I could prevent every other family from having to feel the pain my mother, my sister, and I share."

"Sometimes I wish I could save the world, too. When I was a little kid, I'd pretend to be a superhero that had the ability to heal every disease, broken bone, and stomach ache."

"But what if I could've done something differently? I should've been able to save him, but I didn't. If only I had worked harder or more thoroughly. I should've stepped aside and let the other surgeon take over, but I let my own nephew die on my table." More tears began to fall.

"Oh, Addie," he said, pulling me into him again. "You did exactly what Kaci wanted you to do. She wanted what was best for her son, and she knew you were it. You didn't mess anything up. You didn't forget to do something important. He was too sick to start with."

"He needed a new heart, but he was so small. A matching donor probably would never have come along, even if we tried to wait on one."

"See, you did everything you possibly could have."

"I know."

"If you really do believe that, you shouldn't hold onto it."

"I know. Damn it." I looked down at my beeping pager. "I have to go. 911, and I look like shit."

"No you don't. Here let's try this," he began blotting my face with a tissue, then cleaned the watery mascara out from under my eyes. "Shake out your hair and no one will even notice your eyes are a little puffy."

With a quick kiss, I rushed out of Mark's office and up to the maternity floor. Stepping out of the elevator, I ran toward the commotion at the end of the hall.

Before I said Derek knew about Addie's nephew, but given their argument earlier, I think it's best that he have no idea why she gets so attached.