Kingdom Hearts II Where?

hm, has anyone wondered where the Organization 13 peeps go after they die? Do they go into darkness? Or join their counter parts??? @-@ Or do they go into a moon thingy like the Heartless?? Because after you kill them, they disappear..so..o.O What happened to their Original selves anyway? Did they get lost to the darkness? Or did they get killed (by a heartless maybe) and have just enough heart power to survive and be made into a human Nobody? D: I wasn't paying attention when Yen Sid told me all this junk -.-