jade_1459 suggested a Doppelganger Challenge, i.e. "bringing in a double of a character... maybe Rod revisits our Atlantis? Or maybe some weird alien technology backfires and suddenly Atlantis gets swamped with doubles and triples of everyone! (Can you imagine the terror the science team would feel if there were two or three Rodney McKays? Or just how high Sheppard's blood preassure might crawl if suddenly there is a Caldwell looking over his shoulder everywhere he goes? Or maybe a frowning Elizabeth around every corner?)"
Yes, it's time for clones, quantum mirrors, lookalikes, or, as
ellex42 suggested, "Evil!Alternate Universe!McKay! With beard (because we all know that evil alternate universe doppelgangers have beards.)"
Today's May 21; stories will be due June 4 at midnight eastern.