Whenever one-way jumpers from the past show up, it’s up to Mahler to shuffle them off to
the moon where they won’t present any danger of infection to the rest of humanity, but now
Mahler is faced with a two-way jumper.
Even a cold, a common cold, would wipe out millions now. Resistance to disease has simply
vanished over the past two centuries; it isn’t needed, with all diseases conquered. But
you time-travelers show up loaded with potentialities for all the diseases the world used
to have. And we can’t risk having you stay here with them.