If they’re not anywhere on the main continent, and not on Starfall, the only two options are 1) they went deep underground with one of the subterranean civilizations, or 2) they took the train through the “stargate” to another world and decided to start over.
Any other option would be extremely improbable, but given the current plotline, who’s to say what’s even impossible any more?
Take the time you need to take care of what you need
Any other option would be extremely improbable, but given the current plotline, who’s to say what’s even impossible any more?