River dreams reality, and reality dreams her. She doesn't know which one is more quantifiable. Sometimes this matters.
Her dreams take parts of her away.
She likes to wander at night while Serenity breathes around her, when dreams have flimsy borders and invite her to trespass. River lingers on the good dreams, the happy dreams, the dreams that make her feel things she forgets she never knew.
Zoe dreams of little girls, little girls with brown skin, skinned knees, and bright blue eyes. Little girls who are safe and wanted, and who say, "Mommy," like it means everything. Beside her, Wash dreams of wide open spaces. Stars, planets, blue skies with sunrises bursting over the horizon. Wash's dreams swoop and fly, and trace the smooth lines of Zoe's body.
Kaylee dreams of moving parts fitted together like puzzle pieces. Sometimes those parts are broken, and Kaylee's hands are covered in grease. Sometimes she dreams of Simon, Simon's hands and mouth. River watches those, too, because Kaylee sees Simon so differently, and her sight thrums with joy and flaws. River always sees two Simons: Simon now, with how Simon looked as a boy superimposed on her eyes.
Simon dreams of hospitals, clean and white. He dreams of Osiris and its tall, gleaming buildings. Sometimes he dreams of Kaylee. Sometimes he dreams of blood.
River dwells on Jayne's dreams when he dreams of his mother, her face lined and hard, but kind, her red-knuckled hands knitting sweaters. Slapping Jayne's hands with a wooden spoon, cuffing his ears, swatting his backside. Jayne's softer than he looks.
Book's dreams frighten her, and River has learned not to visit him at night. Not ever.
Inara dreams of many things: Sihnon, music and dancing, and oceans of light. Sometimes she dreams of Mal, and when she does, River always feels her awaken with wet eyes and anger.
Mal dreams of bad things. Confusing things. Torture, pain, shrapnel, and noise, always too much noise. Loss, guilt, and so much fear it makes her tongue taste sour. Sometimes he dreams of horses and rough men, and those dreams are warmer, but lonely. Longing. They make her sick for a home.
River likes it best when Mal dreams of Serenity. He dreams of Serenity, and Serenity dreams of him. River sits outside his wall with her hand pressed to metal, and feels them dream each other.
They feel whole.