Written up for about five replies ago --
>To Mugetsu, "The world outside Gensokyo, apparently eleven years in the future, where we found the real body of the waking dream that Gengetsu encountered. Presumably. Another ally, Patchouli, attuned this lodestone to the energy causing all these rifts and fissures. Ran figured out a... rather uncomfortable way to travel to that place and time, and when we explored, the lodestone led us straight to Maribel as she slept."
>To Mokou, "We already appear to be in an alternate timeline. I don't think it's much more implausible, unfortunately. Or it might be that Maribel dreams 'into' other real locations, or other real times, which... well, makes the other side of the explanation more alarming."
>"And it strikes me as a possibility, Ran. I don't know how or why, but given the connection between Gengetsu's powers and what she was looking for, the implications of finding a waking dreamer might have been greater than anticipated... especially if there's some other unknown power of Maribel's that threw things further into chaos. I doubt her resemblance to Yukari is a coincidence..."
>"Though it sounds like you might have an idea how to check whether Gengetsu is in Maribel's dreams?"
EDIT: Also, Yukari's dreams.