Steve + Tony Survival H/C
Thought I had this bookmarked, but I guess I lost it! Pretty sure I read it on AO3.
General setting is in a forest, I think? Steve and Tony have been stranded. For some reason, Steve can't speak and Tony lost the ability to see. They have to work together to make it out alive...there might be some magic involved, but my memory is fuzzy. IIRC there was a scene where Tony fights some monster and nearly drowns? Can't remember if it's gen or Steve/Tony.