Board Thread:General Discussion/@comment-27907368-20160528162922/@comment-27907368-20160528220552

They were sealed behind the barrier in New Home and they walked to the Ruins, set up shop, and at some point feared the humans no longer and returned to live next to the barrier in New Home. ^^' I think.

After they officially founded New Home, the Asriel/Fallen Human deal went down, and Toriel walked back to Home or Ruins.