Natural Selection

Science Fiction Seven young people from seven different worlds. Each find themselves being pursued by mysterious beings whom only they seem to be able to see; and not just beings, machines the like of which they had never imagined. They are attacked. They are taken. Their last memory only one of blackness. Waking, they are in shells which open up onto a another world, one from which neither of them has been taken. Who has done this and why? The answer is revealed, but not before catastrophe strikes.