Like Ships That Collide in the Night (слэш)

“Do you not remember the prophecy? The serpent has awoken! You need to leave here, now!” He batted a grenade as well as a couple of arrows out of the sky, not sparing a look for Thor’s idiot companions.
“You speak of fairy tales,” Thor managed, catching himself on the metal hull of the airplane, cape and hair whipping in the wind.
Loki opened his mouth to let him know how much of an idiot he was. His voice died in his throat as he was hit by another shock wave of fate. The Norns’ tapestry was torn asunder and woven anew.
**
Or: The one where Tony Stark turns into the Midgard serpent and Loki has to save his brother from himself.