It was either that, or they discovered Atlantis, and pulled up anchor to—no pun intended—land there. I am surprised the Doctor, who—no pun intended—ought to know better, didn't know to remember to consider contamination issues when he entered to colony... But all in all, this was a pioneering read in the limitlessness of new frontiers.

Fanciful, maybe, but oddly satisfying. Much better to think they went off to a better place then the usual theories about their fate.