AN: I do not own the Harry Potter series.

Chapter 1: The Pregnancy

Lily is pregnant. That's the thought that kept reappearing, day in and day out, for James Potter. He and Lily had married straight out of school, were happy with each other, were viewed as the perfect couple when thoughts weren't on the war and mass murderer Dark Lord. There were many reasons for the loving husband James Potter to continuously think of Lily's pregnancy, and some were more palatable than others.

For example, he was happy to be a father, to have a proper family.

But he was also happy to have an heir to the Potter line.

But he also couldn't be sure of whether or not the child would be male, and therefore able to inherit the Potter wealth and political responsibility. After all, the Potters were an old and mostly pureblooded family, whether the occasional muggleborn wormed their way into it or not.

James knew he had to have an heir, and that that wasn't a guarantee. And maybe that's where things started to go wrong for the Potter family.

But he devised a plan based on the knowledge that Lily's child may not be born male and there may not be time to have another one, again without the guarantee of a male child, due to the war. Nobody could say a marauder didn't know how to plan and plot and devise, after all.

The plan James chose was foolproof, so long as he could explain his reasoning to Lily, who had taken to the wizarding world like a duck to water. The plan was quite simple, really. All he had to do was cast a nice, easy charm he had quickly developed for this specific purpose on Lily to ensure a male child would be born. Who cares what the repercussions of that could be depending on what the child's sex was without the charm? Surely, using an untested and rushed charm would have absolutely no repercussions on an undeveloped fetus.

James explained the need for a male child to inherit the Potter assets to Lily, and she agreed. After all, she was a pureblood's wife at the end of the day, whether the blood supremacy and ingrained desire for 'normality' in every pureblood's mind reared its head or not. She knew that so long as she acquiesced to these small things, she would be granted larger freedoms, like pursuing a charms mastery once the war was over and done with. Besides, at the end of the day she wanted a family. She would still be having a child, whether the charm was used or not. So, really, there was absolutely no reason not to say yes to James' request. To her knowledge.

So, the charm was cast. It's just a shame that it wasn't cast properly, or maybe it should have been researched a bit more, or checked for mistakes, or whatever other reasoning one can come up with to explain the results.

Once the charm was cast, James and Lily were perfectly happy individuals. When the twins were born, one female and sickly, and one male and strong, it was obvious James had used the charm successfully. Because really, why would there be any reason to suspect James had failed in creating a spell with no side effects when he hadn't even consulted someone who specialized in spellcrafting to double check his work?

Only, it wasn't successful. Or maybe it was and just wasn't a well thought out spell. Sure, there was a physically male child that came from Lily's womb, but what of the sickly little girl? How did that charm affect it?

Maybe it leeched all her magic and vitality to the little boy.

Maybe it adjusted 'her' developing mind to be a 'him'.

Maybe it gave her (him?) a life-threatening disease.

Or maybe, just maybe, it did all of the above in different phases.

After all, nobody said new and relatively untested charms were completely safe and side-effect free. Especially when not properly checked before use or actually tested. Really, one should at the very least test their recently developed spells and study long-term results and side effects before using them on one's spouse. But, again, as one couldn't say a marauder couldn't plot, one also couldn't say a marauder thought of things long-term. Just look at the attempted murder of Severus Snape via werewolf for a bit of evidence of that.

And with no one the wiser of the significance of the mistakes made in the nine months leading to their birth, two more Potters were born into a world at war. It really was a shame how unlikely it was that both would see a world at peace at the same time.