The characters of the "Thor" comics series belong to Marvel Comics. I use them here only for my own amusement, and not for any financial gain.
Asgard is located on an island in the river Hvergelmir, the great river that has its source under the three roots of Yggdrasil. Sometimes Thor goes down to its banks, to watch the water. It makes a sound like music, but that's not what he hears. Baldur's laughter sounds, clear in his memory. He hears his brother Loki's cries, and the challenges the three of them used to throw at each other.
"I can swim across the river faster than you can." –
"No you can't. You'd be too scared."
And, inevitably throwing cold water on their pretensions, "neither of you is going to swim it," Loki says. "The current is strong, and will carry you down to the Urd-spring if you go out too far. Do either of you really want to face the Norns?"
The three weird sisters who rule over the fate of the Gods: Thor can't even picture them, much less imagine standing before them. He looks at Baldur, and sees the same shudder go over him that he feels going over himself.
"Are you scared, Thor?" Baldur's away like a fish; Thor can see his white body flashing through the water. "Only cowards are scared," he cries from two pools down. "Perhaps Loki's a coward."
"Are you?" Loki's skinny little body stands foursquare in the shallows, legs apart, both hands fisted. "Coward!" Thor gives him a teasing splash. "Coward," he says, "cowardy, cowardy custard."
"Am not." Loki's brow furrows the way only Loki's brow can furrow. "Do you want to get caught by the Norns? There are three of them," he says, "but they only have one..."
But Thor and Baldur have stopped listening. "I can swim across the river faster than you," Thor says, and, "Can not." Baldur's already halfway to the next pool as he says it.
"Come with us," Thor calls back to the third brother. "Don't stay in the shallows like a coward."
It's three of them swimming from pool to pool after that, that's what he remembers. Three white bodies amid the silver spray, three sets of laughter ringing together. And then Loki catches up – somehow. And then he ducks both of them in the next pool. Was his laugh a little sharp when the other two came up sputtering? Was there anger in the flash of his green eyes? But no, he can remember none of that, just three brothers having fun in the water.
His shoulders are heavy, as he turns to go back to the Great Hall. His smile feels stiff on his face. Then it dies away altogether. Would anything have been different if they had faced the Norns that day? Could he have saved both his brothers if he'd just known what destiny had in store for them? Loki says that it is all set, and even immortals can do nothing but play the roles fate has set, but Thor isn't satisfied with that. He won't let himself be, and he won't let himself forget his brothers, the one who rests now in Valhalla, and the one who will never rest, chained in a cave until Ragnarok.