I'm kind of confused of what happen on the Battle of Red Mountain that made them disappear? Were they killed or just teleported to another Dimension? My ES Lore isn't the greatest
Underground? Space? The Moon? Whichever makes more sense.
Short answer, they fused with Numidium. Longer answer (source included): imperial-library.info/content/final-report-trebonius
^ they say how they disappeared but where to is a mystery. In one Dwemer ruin where they would have been there is only piles of ash...
The Dwemer's disappearance is unknown, even the scholars that delicate their life to find out what happened to the Dwemer still do not know. The best answer is the Dwemer attempted to play god and got turned to dust.
What do you think?