Kidnapped women, of course, have one purpose and one purpose only (same as on Earth, actually) and that is as breeding material. The plan is to create slaves/replace the infertile human race of the future/create human cattle ("much cheaper to breed them here on Hashkewahee, Mr President than fly all those trans-light jaunts to pick up food directly from Earth! It's all right for the rich Salamanderoids with their wild Earthling steaks but the ordinary working Reptiloids of this planet just need to get cheap meat on the table". There is an alternative theory that aliens from a rival planet are also breeding humans for food. But on Earth. Their Walking Fishoid race has invested heavily in MacDonalds, KFC, Pizza Hut and Walkers Crisps to ensure that come harvest time Earthlings will be fatter and more delicious than ever. Corduroy wearing, pinko, liberals on their home planet complain about the quality of life of the poor Earthlings but that doesn't stop them eating us.
Reptiloid Alien/human skinsuit hybrid
The third way that objects disappear (and the theory I favour) is that of the multiverse. We are all constantly whizzing through myriad alternative universes where most things are the same but certain key things are different (some Mongolian peasant has three not four children, for example. Will it effect me? No. Unless the missing fourth child decides to be the new Ghengis Khan). Occasionally, and this is the point, we drop into a universe where every single thing is the same but my metal ruler doesn't exist. This has just happened to me. I was searching through my lead pile last night and found over two dozen Perry metal Napoleonics (French and Dutch). Well, I thought I'd base them up so went to the drawer to find my metal ruler and it had gone. Much fruitless searching and then my wife said that my 13 year old daughter (who has just overtaken my wife in height - 5'6" is quite tall enough, thank you) had been using it on the kitchen table. I cleared everything off but couldn't find it. Mydaughter admitted she had been using it and had left it on the table. I told her that her chances of getting the Dancing on Ice Live Tour 2008 DVD were looking pretty slim if she didn't find it. Nothing. I am unable to make bases.