Loki has always been the one to weave things together. Since the first time they went under, Thor in dreams is a hammer, blunt force and spectacle, but Loki is a needle, sharp, directive, pushing between. The dreamspace pulls into shape around him. Bricks stack themselves, murals stretch open before his feet, water runs into icicles, hard and fluid-looking. His own form shifts at a thought, clothes reweaving and hair caught mid-curl, muscle and skin momentarily slippery with change.
He likes the challenge, relishes the paradox of it all: the freedom of the impossible held by the limits of the unknown, the unknowable, the inexpressible wariness that sends a shiver through the spine of every dreamscape, rippling out from where it’s prodded. He likes the way Thor smiles at the shudder in the air, anticipating the crash.
The thing about Limbo is, there are no constraints. The only limits are their own minds, and they have built too much between them to so easily set their foundations unstable. Limbo stays resolutely still under their feet, even in their last days, even as Loki nests the impossible inside the wildly improbable and does his level best to make it shake from the sky down. Fish swim in the air, the parlor doors open to the vastness of space on one side and the rounded shell of a nucleus on the other, the library houses pure oxygen and a sun between its walls of books and somehow doesn’t burn. Loki is visibly, plainly desperate, and still Thor’s face stays flat, his eyes shadowed.
What’s wrong? he says, his mouth etched flat with worry. Brother, what are you trying to prove? and Loki trembles at his side in all the ways Limbo won’t.
In the end, it’s simple, appallingly so. Thor’s totem should be a closely-hidden thing, but Thor has always been easy to loosen under drink and the speed of Loki’s tongue. Thor guards his secrets as securely as he does his mind—which is to say, not at all, at least where Loki is concerned. A tip of a bottle, a flash of a grin, a swivel of his wrist, and Loki is holding a carbon-spun copy of Thor’s keys. A mallet dangles off the ring, a souvenir keychain from their time in Norway that the dreamspace weighs too heavy for any but Thor to lift, and Loki whistles as Thor’s wide eyes track its lazy spin around his finger, as the ale in the glass by Thor’s knee quivers.
From there, it’s a matter of time. A few more things fall each day, some slipping, some jumping, some knocking over under Thor’s stumbling steps. Loki watches, burns alternately with satisfaction and impatience, and the smile he can’t quite stop when Thor finally tracks him down on the roof of the tallest building they ever made feels wicked in its relief.
As a—test? show? Either, neither, he won’t say—Loki raises them another storey, and another ten after that. Thor stands on the edge of the roof and bows his head to watch the ground drop seamlessly away. The sky cracks down the middle with lightning and rumbles in the aftershocks violently enough for Loki to feel it to cores of his bones. Thor's grin, when he looks up, would split his face to the skull if it were a fraction wider.
Thor’s hand is firm in his as they step off the roof, firmer still as they blink awake on the floor of their living room. His skin is warm, his smile warmer, soft-edged with the last traces of medicated sleep and curiously tame. His other arm shifts at the wrist at his side, hand buried deep in his pocket and bunching the fabric of his pants as it flexes.
He’s gripping something, Loki thinks. His keys, maybe, or his own fist, cutting his fingernails into his palm for the shock of pain; a way to ground himself. A way to wake himself up.