STOP. READ THIS NOW.

SGA/SG-1 (sort of): Here Is No Water by frostfire_17 (Sheppard/Mitchell).

I know I am years late to the party. And if you haven't read this already, lord knows why, then you really need to stop what you're doing and do yourself a favor and read it right the heck now. The most intense, riveting, smart, thinky, and brain-meltingly hot thing I've ever read.