Thor stops breathing. He looks up at Loki, who has just entered Thor's room, looking pale and grim faced.
“What?” Thor says faintly, wishing to have heard wrong. Or misunderstood. Maybe Loki is supposed to go somewhere and is running late. Maybe he wants Thor to give him a lift with Mjölnir.
“My period. It hasn't come.”
If there is one thing you don't want to hear when you are regularly fucking your intersexed brother, it's that.
“But we've been careful.” Thor says, getting up and walking on suddenly rubbery legs to Loki's side.
Loki's expression is dark. “Not careful enough.” He says bitterly.
They stand in front of each other for long moment, silent as the horror of their situation starts to sink in. If Odin finds out…
Loki looks up at him, face crumbling, tears welling up in his green eyes, “I don't know what to do Thor, I don't know! What, what should we—” He breaks off, voice lost to a sob. Loki's tears make him look young, like a child, and suddenly Thor can't see anything but his baby brother, asking Thor, the eldest, to save them.
Thor pulls him in and embraces him, letting Loki hide his tears against Thor's neck. “You're sure?”
Still crying, breath hitching from panicked sobs, Loki nods. “It's the second time. The first one I thought I had just skipped…” Loki's cycle has never been regular, so it's not impossible, but he usually doesn't miss his period all together.
Loki's hands claw at his back, like a frightened bird hanging on to a tree in stormy weather. “I just know Thor. I can feel it.” He whispers, voice shaking, destroying all hopes of a false alarm.
“We'll leave,” Thor says, clutching Loki to his chest like he’ll be ripped away. If anyone catches them he will be. Thor is the older one, the penetrator; he's the one they would normally blame. But Odin can't afford to lose his heir, and Loki is so often called a liar and worse… as much as Thor wants to deny it, faced with this he can't deny their father's favoritism. “We'll go to Vanaheim. Seek refuge.”
Loki nods, but his tears are still flowing. Thor grabs him by the neck and meets his eyes. “No one will take our child.”
A shiver passes through Loki at Thor's words. “We're brothers, it will come out wrong.” He blinks, eyes wide and glassy, “We're brothers.”
Thor looks away. It's too late to regret their actions now. It's too late to go back to how they once were. They knew they were brothers when they started this.
“It doesn't matter. We will still love it.” Thor says, hoping he can make that come true. Right now he wishes it didn't exist.
There's a noisy clanging from the hallway; guards in plate armor moving past on patrol. It makes them both jump.
“…Go pack your bags,” Thor says, voice low and hurried, “Meet me by the Bifrost in an hour. We'll say were going on a hunting trip.”
Loki nods, then hesitates. He looks to the side, biting his lip, then back at Thor. “I know another way. If we use it, they won't know where we went.”
Thor is too stressed to question his brother's ability to move between worlds. “Is it safe?”
“Safe enough.” Loki replies.
“All right,” Thor breathes, pulling Loki close and kissing his forehead, eyes closed. “Don't worry brother, I'm here. I've got you.”
Loki squeezes his hand, returning the sentiment.
In a small cottage on Vanaheim, Loki gives birth to their child, screaming from pain and utterly alone aside from Thor.
Thor, who doesn't know what to do— how to help, and can only hold his brother's hand and mumble soothing nonsense.
Loki falls back into the pillows, sweat soaked and sobbing. Thor has seen him cry far too much these past months; his sensitive little brother with the delicate heart, who could never hide his tears.
“There's something wrong,” Loki pants, looking pale and far away. He squeezes Thor's hand but his grip is weak. “Something feels wrong, I can't—”
“You can,” Thor insists, because there is no alternative he can accept, “You're the son of Odin and Frigga, my brother, and you are strong.”
Loki just blinks up at the cobwebbed ceiling, too slow, too pale. “I’m hot. It feels like I'm burning.”
Thor glances at the sheets; they are soaked with fluids and blood. If Loki has an infection, a fever, then Thor doesn't know what to do. There is already so much blood.
“You can do this…” Thor says again, but silently he is beginning to fear that Loki can't.
Loki nods. He looks dazed, but by the next contraction he pushes again, veins in his forehead straining. Then he screams.
The baby crowns, and Loki cries “Take him, take him, you have to turn him!”
Their baby is born into the world blue, cold and quiet.
Thor pulls him away, heart breaking. It's a boy. He's still connected to Loki by the umbilical cord—Loki who is panting harshly, Thor can hear him, but he can't pull his eyes away from their son. Their son who is quiet and cold and blue.
Thor thinks he is dead. He is trying to get his voice to work, to push words past his narrow throat, to tell Loki, when the boy opens his eyes.
They are blood red.
Thor almost drops him. The baby makes a high thin sound, resonant, and nothing like an Aesir babe's cry.
Thor's first thought is that he is hallucinating, but the smell of blood is too real, too near. The next is that the baby isn't his, that Loki laid with someone else—but when he turns to his brother, Loki is blue too.
What Thor couldn't recognize in the infant, he can in Loki. Blue skin with swirling white lines. He has seen that before, but only in history books and nightmares.
“Thor…?” Loki opens his eyes; they are red too. Red and faintly glowing. Thor flinches back.
“Is he—I can't hear him, please say something,” Loki begs, still searching and diffuse. He doesn't seem to have noticed his changed skin.
Numbly, unsure of what else to do, Thor kneels next to Loki and hands the strangely quiet but alive baby over. He wiggles against his mother's chest, searching for sustenance and latching on with a grunt when he finds it. Too mobile for an Aesir babe, bloody eyes too focused and clever. He was born to survive a harsher world. Not Aesir at all.
Loki runs a shaking hand over his downy head, still weak, struggling to hold him. “His hair is blond, like yours.” He smiles, but then finally notices the color of their son's skin, “What's wrong with him?” He asks, voice rising. Then he spots his own blue hand and goes still. Very still. “Thor?” He says, voice small and brittle, staring at his own hand like it's a viper, “Thor?!”
Loki's voice is the same as before, and he sounds frightened, panicked, calling for his big brother to save him. It's what finally makes Thor snap out of it.
Loki doesn't know what he is. He can't see his own red eyes.
Thor grabs his hand, trying not to wince at the rough cold feel of it. This is Loki, he tells himself, not a monster. “Loki…”
Their eyes meet, blue and red, Aesir and Jotun. Struck dumb, Thor says the wrong thing. “I-I don't think we're brothers.”
Loki's expression shatters.
Between them, their son starts crying. Their Jotun son. Thor is father of a frost giant. He feels sick.
Loki isn't his brother. Odin's favoritism finally makes sense. They're not brothers. They're not brothers…
Thor realizes that he is crying too.