So why is it that we don't believe that there two are also the twins' parents? The fact they are Elder, right? I know it's probably old news, but didn't pretty well all of the Elders go through the 'change'... Even though these two appeared not to, maybe it just wasn't a change you could percieve from the outside? So the couple we meet at the beginning of the book are Isis and Osiris from the past (pre-change), and the parents are Isis and Osiris post-change, using false names to try and protect the twins from their (Isis and Osiris') past selves.