Author's Notes at the end

Chapter One: Lunar Revolutions

New York, Now

"Oh, God, let me die now," Darcy mumbled to the ether. Her head felt like Jane's boyfriend was using it to rest Mjolnir on top of her skull and her whole stomach was one enormous ache. That it wasn't going to kill her didn't do anything to make her feel better. She hugged the hot water bottle closer to her gut.

She hadn't even made it to her own bed, just collapsed on the couch like a deflated jellyfish. Ten more hours, maybe twelve. Then she'd think about living. Until then, Jane's suite in Stark's shiny building was a morgue. She could hang a sign on the door – House of the Dead, go away until the new moon.

Voices approached in the hall, growing louder as they came. Should have put up that sign. The keypad beeped, peevish, as someone fumbled with the lock. "Please god," Darcy muttered, to no deity in particular, "Go away."

"Friend Darcy! We have returned!" And speaking of gods…Thor's voice boomed through the apartment, nearly drowning out the door slamming open. "And we have brought Lady Sif, as you pled in your missive!"

Oh, God, Jane and Thor were supposed to have brought Sif with them today, who was to have let Darcy interview her about Asgardian naming conventions for different kinds of kingly decrees. Because Sif had said something about how Odin spoke with the Word of God, but sometimes he muttered, and sometimes he said pretty please, and sometimes he opened his mouth and blasted the multiverse with plasma. Or so Thor said, and Darcy had seen the look Sif had given him, and this would absolutely work for her thesis. Darcy was sure of it. As soon as her body cooperated and let her brain work again.

Darcy struggled up on one elbow, then lay back down with a groan, squeezing her eyes shut, one arm hugging the water bottle against her abdomen, and her other hand pressed against her forehead.

"Friend Darcy! The day is yet young! Why do you slumber?"

"Thor, darling…inside voice." And that was Jane, her words sliding like cool water over Darcy's ears. Thor went silent, except for the rumble as he breathed. Darcy could feel it on her skin, which cramped and crawled in time with her stomach.

"Darcy, fair maid, you are unwell! Have you been injured? Show us where you bleed! Was there an attack? We heard no sounds of battle!"

And Darcy knew that Thor meant well, and under other circumstances she would even consider him sweet, but right now if he didn't shut up – or at least lower his voice so it didn't echo - she was going to battle his hammer where the sun didn't shine.

"Easy…she's going to be fine." The couch shifted as Jane perched next to Darcy. A gentle hand touched her cheek. Darcy scrunched her eyes tight against the tears that welled up. "Oh, honey, started early?"

Darcy nodded, sniffed, "I hate being female."

"Shall we summon a conjurer of the elixir of Tums?" Darcy had supplied Thor with a bottle of antacid on the one day the Asgardian had gone to the Mendez buffet and over-eaten armadillo eggs until he gave himself a stomachache. Ever since, Thor thought every pharmacist an alchemist and Tums a cure for every aliment.

Jane was far more practical. "Did you take something?"

Darcy nodded miserably, refusing to take her arm off her eyes. "An hour ago."

"There, there." Jane patted her arm. Darcy smacked at it. God, she hated that. "I hate being female." She did. If only because the world was full of not-female people, like Thor, who had no idea how good their lives were. And who predictably misunderstood her.

"What is this? Fair Darcy, are you with child? Where is the father? Why is he not here to attend to you?"

"Thor, honey, hush. It's not that." Then, more quietly, "It's not that, right, Darcy?"

Darcy groaned. "Please. It's the Avengers' Tower, Jane, there is a maximum of zero privacy in this place. Zero. You'd know. They'd all know. And if I was, I wouldn't be feeling like this." She hugged the water bottle harder. "I hate this. Every single month."

Jane murmured encouragement, in the same breath as another alto hiss of sympathy. Even with her eyes shut, Darcy knew that was Sif, who was regal and lethal even as she cuddled white fluffy kittens.

Thor, though… There was an honest-to-God (specific gods, this time, not including lying snake-mouthed bastards like Thor's brother) pause, and when he finally spoke, his voice – a stage whisper that could reach Mars – was suddenly enlightened. And distant. "Ah. Yes. The – ah- this matter, of, ah – Fairest Jane. Is there anything you require?" Thor's voice, no quieter, grew more distant. Like, across the room distant. "Any task, no matter how great, or how small, I am at your service, my heart. I shall go to the Man of Iron, and inquire…"

The door shut on whatever it was that Thor was going to do. In the silence that was left, Darcy slowly lifted her forearm and peeked out. Jane was still staring at the (still shut) door, while Sif had added amused to the point of snickering to regal and lethal.

"Did I just – did that – was that Thor running away?" Jane, incredulous. "From…from…menstruation?"

The corners of Sif's mouth twitched. "My prince and my brother of battle fears no foe, suffers no fear of any man, save alone my King Odin Allfather. No matter the enemy, Thor would never act the coward."

Darcy snorted. "That was Thor running like a cat with a sausage."

Sif grinned. "Aye."

Jane suddenly looked embarrassed. "Do…ah…Sif, forgive me if I'm impolite, but this is something that, ah, the women of Asgard…"

Dammit, Darcy thought, I'm supposed to be the humanities major here... Her notebook was in her purse, which was kicked under the table by the door. She wasn't getting up to get it.

"Oh, aye." Sif looked around, found the backless hassock that Thor favored, over the more fragile framed chairs that scattered the apartment. "May I?"

"Oh, sure," Darcy said, in the same breath that Jane gushed, "Yes, please, sit wherever you like."

Seated, Sif went on. "It is with us as with the women of Midgard, with us, and the most of the nine realms. The Jotuns – they shift forms, male to female and female to male, and I do not know their particulars. It has…not come up, on the occasions that I crossed swords with them. But among the Aesar, yes, we gain adulthood, we bleed, and come into fruit."

"Is it, well, taboo to talk about it? I mean, with men?" There, that was a proper question. And yeah, it was more like anthro than polisci, but at least it was in the same neighborhood, as opposed to, say, quasars. Any quasar. All quasars – definitely not local.

Sif cocked an eye at her. "Forbidden? Oh, no – though most men would say the less it was spoken of, the better. Some would say it ill luck to speak of it, when a wife and husband are new to each other, and the woman wistful of bearing. But it comes to all women, even Lady Frigga. And I."

"Is that a problem, you know, when you're out, you know, buckling swashes, and busting heads?"

Sif shrugged. "It is as it is. Some women, they grow weak for a hand of days, from the blood loss. Others – " She waved a hand at Darcy, the water bottle, and the (mostly dry) washcloth on Darcy's hairline. "Some it takes thus, and there are some who are fierce in the lists and on the drilling floor, but there are a multitude of other pursuits a woman may follow. A weaver, a scribe, a tale-smith, a healer."

"Oh." Well, that sucked – even in Asgard, nasty periods cut you out of the action.

"And we have some potions, of course."

"Potion – you have Motrin?" When Sif looked blank, Jane went on, "Medication to ease cramping?"

"Aye, here." Sif dug into one of the pouches on her belt, came up with a bit of folded paper. "These leaves, steeped gently in clear water, and then drunk when cool." Her face sudden turned wistful. "Loki excelled at herb-craft, and he knew how to search out the most potent plants. On long journeys, he would gather them, and bring them to me."

Darcy's hands were suddenly much less grabby after the little packet of super-Motrin. Jane was faster anyway, and intercepted the paper package.

"No. We need to test it first, make sure it isn't anything you're allergic to." To Sif, she said, "Just to be safe. Darcy isn't going to feel any better if this makes her start vomiting."

Sif seemed to accept this without offense. "Take it – I can easily bring more, when I visit again. Darcy –"

A pounding at the door – suspiciously like a boot kicking at floor level - cut across whatever Sif was about to say. "Jane Foster, Lady Sif! I have consulted with the Man of Iron and the Eye of Hawk, and have brought the Lady Natasha."

Another voice said quietly but firmly, "No, you didn't. I brought myself."

The door opened and Thor nearly fell through it, his arms full of round tubs and square boxes. "—and sustenance. I brought sustenance, such as the Man of Iron stated that the Lady Pepper Potts found strengthening. And –" he scowled at the SHIELD agent peeking around the doorjamb. "– I also brought the Lady Natasha." The topmost tub trembled, then slid to one side, taking a box with it in a suicide plunge to the floor.

Romanoff took two fast steps forward and caught both of them before they hit the tile. "No, you didn't. I just followed the person who was unloading Pepper's entire stash of mint chocolate chip and cherry bon-bons." She set the ice cream and box of chocolates down on the coffee table, then turned back to Thor and began relieving him of his burden. "Because," Natasha went on, completely deadpan as she stacked chocolates and tubs on the table, "if I'm going to have to be in the same time zone when Pepper finds that her cache's been raided, I want to have at least tasted it."

She handed two boxes to Sif before setting the last of the ice cream on the table. Thor strode across the room and knelt by the couch. "Friend Darcy, I regret that I can offer no more than this –" He held out the pilfered bon-bons in a massive hand. "Will the cherry-chocolate, do you think, help you recover?"

And when a guy bellowed that at you, especially the boyfriend of a good friend and whatcha-call-it-mentor, what was a properly enlightened and self-determinate gal to do, but take the chocolates, smile, and say, "Thank you, Thor, you are the most considerate brawler I know."

Jane leaned in, kissed his cheek. "Well done, sweetheart."

Thor grinned like sunrise and bounded to his feet. "Friend Darcy, Fair Jane, Lady Sif, Lady Natasha – I am off! Call, my friends, if battle beckons!" When he shut the door, the pictures on the wall trembled.

Darcy lay back down and set her arm back over her eyes, grinning despite herself and the ache in her gut.

Jane sighed. "Wow."

Darcy snorted, completely without sympathy. "You sure know how to pick them."

"You going to be okay?"

"Yeah. Gimme a couple of hours, and some chocolate, and I'll be up and at them."

"Wait. Ladies, we have a problem here," Natasha said, suddenly, urgently. Darcy sat up. "Bowls. We need bowls. And to put at least some of this – " She waved a hand at the defrosting stacks " – back in the freezer. I'm serious, Pepper really will pitch a fit if she finds out that Tony gave away all her ice cream." She began sorting the ice-cream. Jane helped. Darcy laid back down. Sif moved two cartons back into the "keep" pile – and three boxes of chocolate.

As the invalid, Darcy contented herself with opening a box of bon-bons. "Here. Take some. For sustenance. On the way back to Pepper's freezer." Jane took one. So did Natasha. Sif took three. "Are you sure I can't try that Asgard Motrin?"

Jane laughed, patted Darcy's arm, and didn't slam the door when they left.

[end]

Title: Learning Lilith, Claiming Kali - Chapter One: Lunar Revolutions

Summary: Biological implications of being a hetero-normative homozygous-X hero – fluff, chocolate, heartache, and blood.

Characters: Darcy Lewis, Jane Foster, Natasha Romanoff and Sif. Movieverse canon relationships.

Author's Notes: Set in movieverse, post-Avengers. Thanks to Flora and Kernie for beta - for this section, special thanks to Kernie, Thor partisan extraordinaire, who made me change this section significantly for the better.

Disclaimer: Not mine; they were broken when I found them.