Title: Axiom 
Author: R.C. McLachlan
Series: Part Three of Theorems (previous parts here and here)
Pairing: Loki/Tony
Word count: 10,542/? words
Warnings: Major character injury, brain death, coma, explicit sex, explicit language

Summary: The term for a mathematical starting point is an axiom. Loki does not know if there is a word for an ending.

Loki closes his eyes against the wind and feels as though he’s vibrating inside, resonating, oscillating, and there is a sinusoidal wave equal to this initial phase, reinforced, hitting him hard, and the fundamental frequency splits into a million multiples. Once he hits the right frequency, he will shatter like glass. Tony would no doubt find the comparison hilariously dramatic.

Theirs was a beginning made of explosions, of amused threats and shattered glass. An axiom to remember. Since Loki does not know the word to counter it, there will be no goodbyes. Not yet. The Earth has a week before he is either found triumphant or burdened with new, terrible purpose.