That question has Lost fans feeling a bit lost. We know that the creepy character, played by Tom Cruise's real-life cousin William Mapother, wasn't on the downed plane's original manifest. And we know that he wants Claire's unborn baby. But why? Mapother is sworn to secrecy. All the show's producers will tell us is that his name, Ethan Rom, is an anagram for "Other Man." Great, more mysteries! So until the show returns Jan. 5 on ABC, here are the Top Four theories on just who the slimy fellow might be.