Given the strength of John's ATA gene, I think he could learn a lot about Atlantis while he's waiting to be THE LAST MAN. Is there linear time inside Atlantis's computers? Or could John and Elizabeth coexist for a couple of millenia inside the machine? What plans could they draw up--just a failsafe--to guide the expedition's decisions in their absence? Could those plans be transmitted in error, and require heroic efforts to get things back on track?