After Eleni left, I threw myself on my bed and moped for ages and ages. Even opening my notebooks didn’t help. My insides were gnarly, like a tangled hose full of steaming purple pus, and I would have written that down if I wasn’t in such a poisonous mood.

To understand why I felt that way, you need a little more background.

You know how I said Eleni was my cousin, but more like my twin? Well, there’s more to it than that.

Eleni’s mom and my mom are sisters, and they’re super close, too. They did everything together when they were little, except, like—I dunno—go to the bathroom, I’m guessing. Obviously, they argued sometimes because Soph has a fiery temper and Mom’s stubborn, but you get the idea. When they each got married (eight months apart), they lived three streets away, which must have been creepy for Dad and Uncle Christos, but Dad said that was normal in Greek families and he liked to see sisters so close. And it helped that Dad and Uncle Christos got along so well. I wonder what would have happened if they’d hated each other.

Anyhow, Mom had my sister, Katerina, six months before Aunt Sophia had Elias. Eighteen months later, Mom had Nicos, and three months after that, Aunt Soph had Kallie. But when it came to us, Mom and Aunt Sophia were pregnant at the same time, and Eleni was born just five days after me. Which is one of the reasons we’re almost-twins.

“I was so exhausted when I visited Aunt Soph in the hospital,” Mom’s told me a thousand times. “I put you in the transparent bassinet with Eleni—course, she didn’t have a name yet—and climbed into Sophia’s hospital bed with her. When the nurse came by, she couldn’t understand why there were now two mothers asleep in the bed and two newborn babies asleep in the bassinet.”

Later that day, the doctors noticed Eleni had a problem. A serious problem. She was going blue and wasn’t breathing right, so they ran some tests. They found she had something called hypoplastic left heart syndrome, which means the left side of her heart hadn’t grown properly.

When she was one week old, Eleni had to have open-heart surgery.

Mom’s told me that story a thousand times, too.

“After the operation, on the seventh night of her life, we were all in the hospital, anxious and numb and waiting for news. The doctors came in looking serious and took Aunt Soph and Uncle C to one side. They said it wasn’t looking good, and we should prepare for bad news. Eleni was so weak, they didn’t think she’d make it to morning.”

Mom always pauses at that part. She takes a long breath and adds, “That was the worst moment of our lives. But later that night, a different doctor came in and said there was one more possibility. She’d read about it, and sometimes babies survived against the odds if another baby lay beside them. No one knew why. She said it was a gamble, but we were all so desperate to save Eleni by then that anything was worth a shot.

“So I lifted you out of your stroller and handed you to the doctor. She carried you into the intensive care unit and laid you in the bassinet beside Eleni. She had a whole network of tubes all over her teeny body, and even though you were only twelve days old, you were almost double her weight. The doctor laid you face-to-face, and we all watched from the window, holding hands.”

I know the rest of the story by heart.

After some time—maybe it was a few minutes, maybe more—I held my little hand out. I stretched my fingers toward Eleni’s face and rested them on her cheek. I can’t remember any of this, of course, but if I close my eyes and think about it, I can imagine it perfectly. All we hear is the other one breathing, and all we can feel is the warmth of the other one’s skin. We have no idea that all around us machines are beeping, doctors are frowning, and parents are crying.

No one knows how, but Eleni made it through that night.

They took me out to feed and change me, but when they put me back, they placed us close together again.

Eleni made it through the next day, too.

And the next night.

And the day after that.

We’ve just taken it day by day ever since.

When she was strong enough to come home, they put us in the same stroller. Aunt Soph thought it would be good for Eleni to have me close by—it would help her heal and feel safe. And it did. And she made me feel safe, too. I can’t remember it, obviously, but I know it’s true because she still does.

We did everything together after that. We have hundreds of photos of us in the same stroller—my scribble of curly hair on one side and her fair silky head on the other. And chewing on each other’s hands, asleep with our heads touching, screaming in kiddie pools, making sandcastles, taking our first steps, and having birthday parties together.

Our families would go into each other’s houses all the time with pots of food, and every year we’d all go to my grandparents’ house with fifty other members of my big loud mad family for Christmas and Easter (and Easter is big for Greeks). Eleni and I were always together. Always.

Eleni had to have two more operations, one when she was five months old and one when she was two years old. Only six in ten babies survive all three of those operations, so now everyone calls her the miracle baby and treats her as if she’s made of glass. She gets away with being naughty and sassy, and they all love her. Not just in our family, but in the whole community. Like she’s a celebrity.

Her condition means she still has to be careful, because her heart isn’t as strong as other people’s. She goes to the cardiologist all the time for checkups, and she can’t do the stuff kids usually do. So we do other things, like make up games and make each other laugh. Since we were babies, there hasn’t been anything Eleni and I have had to do on our own. We’re like one plant with two flowers, or a two-headed cat (or something).

So saying she’s my cousin doesn’t really sound right.

I just use the word cousin because there isn’t a better one yet.