You were not part of a plan. I know someone could think that (and by someone I mean Jack, the only other person who knows the circumstances of your conception): lose one child, make another. If was that was what happened, I didn't do it on purpose. I wasn't thinking of you. I wasn't thinking of anything. I was just empty, and guilty, and sad.

Maybe I was thinking of one thing, or two: how his mouth felt on my skin; how he could make me forget.

I hated him again when I found out about you. How could he have chosen the island over me? How could he have left me alone now, when I needed him? How could he not have known, somehow, that you were coming?

We had been back for almost two months before it occurred to me that something was strange. I had missed periods before due to stress and everything was so hectic then anyway I was not paying attention. There was a new story to sell the world, for one, and my broken probation to deal with, and Claire and Claire's mother moving into my house so that Aaron could sleep in his bed and stop having nightmares. There was James too, and Cassidy: he wanted to be a father now, and she did not believe for a second that he had grown up finally. There was Jack's mother, and Hurley's. There was no me, really; I was somewhere else.

But one morning I woke up and I just knew. The sun was coming in through the window onto my face and it felt like Jack's warm hands, and I smiled and turned to reach for him, half asleep. He wasn't there. But I remembered the feeling of him being there, and I remembered that I had not had a period in a long time, and then I knew you existed.

After everything that has happened, I don't know how I can still be surprised. But you surprised me. I had stopped using birth control when he left. I hated how it made me feel round and unbalanced. He didn't know that, though – would he have stopped if he'd known? Dug a condom out of his bedside drawer? I was so far beyond that kind of caution that night. I had just left my son and I didn't know if I would ever hold him again.

(I didn't grow Aaron inside of me, but I held him against my chest while he slept a thousand times, and felt his cheek grow sticky against my skin. No one had ever trusted me the way that he did. I had never earned trust like that before. And that day I gave it all away: his trust and my goodness, my new life with its spacious corridors and future plans. I had nothing left except Jack. Jack who was broken and haunted and mad; Jack who wanted to go back. So no, I wasn't thinking of anything so practical as birth control.)

I told Jack's mother first, as soon as I took the test. I didn't really want to. I will never tell you this when you are old enough to understand, but I don't like your grandma very much. She always hated me, thought I wasn't good enough for her son, thought I drove him to drink. Maybe blaming me was her way of blaming herself. I had been the one to call her and tell her Jack wasn't coming home. I tried to think of some way to explain to her what he had done, why he had stayed, but there aren't any words that make sense. So I just told her. When I called back, to tell her about you, she was silent for so long I thought maybe she'd put the phone down and walked away. "Mrs. Shepherd?" I asked.

"Thank you for telling me," she said. "I hope you'll let me…"

"We'll work something out," I said.

I tried to imagine how Jack would have reacted if he had been there. I lay on my bed – which had been our bed for a little while – and tried to picture telling him. At first I saw him as he had been the last time he was in my house: drunk, angry, frightened. Accusing me of planning this, of trapping him, of being deceitful and asking too much. Then I saw him as he had been on the island, both at the beginning and the end: confident, capable, kind. He would have smiled at me, I thought, with pure disbelieving joy. He would have chuckled low in his throat and picked me up off the ground. He would have listened to how afraid I was and then held me in silence until I stopped being afraid.

(Which one is more true? I have always been best at lying to myself.)

How could I have made him believe that he had nothing left but death? I hated him for not being there, but I hated myself more for driving him away somehow, for not telling him more often and loudly how much I loved him. I was afraid too: of losing him, of being lost.

Because Jack was not there to tell I told Aaron next. "You're going to have a cousin," I said that night as I tucked him into bed. We both put him to bed then one after another: Claire first, then me.

"What do you mean?" he asked suspiciously.

"I'm going to have a baby," I said. "Not right away, but someday soon. Another baby to live with us here. You'll have to be nice to him – or her."

"Why?" Aaron asked. I could tell he was not overly fond of the idea. There were too many new people now, and not enough of those he knew: he still asked about Jack sometimes, even though I'd told him Jack was gone.

"Because the baby will be your family."

"No I mean, why are you going to have one?" Aaron asked.

"Because you're getting to be such a big boy," I said. "You need someone little to look after." He nodded at that, thoughtfully.

You and Aaron are cousins but you look nothing like my tow-headed little boy. He still asks once in a while where you came from. He is concerned, these days, with where people come from and where they go. But he is coping. We are all coping. You, you alone, thrive.

Claire did not know what to say when I told her. I could see the thoughts churning – if I had my own, maybe I wouldn't want hers anymore – but if I didn't want hers, what would it do to Aaron who still called me Mommy? (He called her Mommy Claire then but now he just calls her Mum.) "When the baby comes," she said to me later, "we can leave. If you need the space."

"Live together or die alone," I said, and so she stayed.

James was disbelieving and relieved that we had caught the plane. (Sometimes I tell myself that I left because I knew about you, somehow, that it was not selfishness or cowardice but love for you that made me leave him there. Another wonderful lie.) "I was so scared after we found out about all the pregnant women," James said, dredging up old history, another way he changed recently, "when I thought I might have knocked you up on that goddamned island."

"I was so mad at you for being so scared," I said. I was glad we could talk about it now. Some spark of lightning that used to exist between us had gone, and now there was only fatigue and friendship and understanding. We could talk now about things we never could have talked about before, for fear of showing our hands.

"It wasn't fear of the baby," he said, "it was fear of what it might do to you to have it there."

"I know," I told him. "That's what made me mad. I didn't want you to love me so much." He nodded and took my hand. I wonder sometimes what would have happened if he'd made it off the island with us the first time. Would he and I have remained lovers? Even if we had, I don't think it would have lasted for very long. We were too much alike: we would have flamed and then burned each other out. He could not have been Aaron's father either. He wasn't ready then.

Everyone knew after that except the person who should have known first. As you grew I wondered what Jack would have thought of the stretched skin over my belly. He had never been one for excessive compliments, but he did look at my body sometimes with a kind of wonder that should long since have been erased from the eyes of a doctor. How could he find my body amazing when he had seen so many hundreds, even thousands? What would he have thought of it as it changed, shifted, groaned under new weight?

And then you came. You were early, which I suppose is fitting given the impatient nature of both your parents. Claire was in the delivery room with me, which I thought was right. She laughed afterward and said, "I didn't know it was so scary for you." I pointed out that all she had to do was hold my hand while the doctor delivered the baby, and she shot back that I was probably having a better time this go around too. This was all the next day. During the actual delivery we were crying too hard to make jokes.

When they laid you against me, your face still red and wet, I was the happiest I had ever been. Even though he wasn't there. Even though so many people weren't there. You were there. You are here now.

You are small still but fierce. Sleeping, as you are right now, you are a dark jewel. The nurse at the hospital said she'd never seen a baby born with so much hair, thick and dark. But when you open your eyes they are green, clear bright green like jungle leaves.

I said I did not plan you, but I did imagine you. In the brief time when Jack and I were happy together, I dreamed you. I thought: not yet, let's enjoy what we have now, but someday. Someday Aaron would need siblings, and Jack and I would want to create something – someone – new between us. Someday Jack would shake off the last vestiges of doubt in his ability to be a good father, his last jealous mistrust of me. Someday I would let go of my guilt and fear that someone would compare a baby born of my body to Aaron and know that I was a liar. Someday you would come. After he left, I gave up those plans. I thought you would always be just an imagining. You were such a faint picture in my mind then I did not even mourn your loss. There were more tangible things to mourn: Jack himself, and Aaron's loss of his second adoptive father.

I still mourn those losses (and more, because I know Jack is never going to call, I will never hear him on my voicemail slurred with pain which sometimes was better than not hearing him at all). But you are the most tangible thing I have ever known.

(Please know: You were not a replacement or an insurance policy. You were not a piece of him to keep or something that would be mine forever.)

Some people wait for years to have a baby. I always thought how lucky those children must be when they came, to be so wanted. (I was, I'm pretty sure, a mistake.) But I could not love you more if I had waited years for you and plotted and planned and prayed. I could not love you more.