Here's a scenario (ALL MOO) that I can't quite discount and that keeps playing in the back of my mind:
Perhaps Leah was in a relationship with a married man but things weren't going well (stressor) for some reason. Possibly the man wanted to break up and recommit to his wife/marriage. Possibly Leah wanted him to leave his wife but he refused so she broke it off. Possibly outside pressure (wife, brother) forced them to break up or at least to pretend to break up (which might precipitate the sudden, out-of-character lying). Lying, incidentally, is a stressor in and of itself.
Perhaps Leah was pregnant by the married man with whom she had recently (voluntarily or involuntarily) ended a relationship (stressor).
Perhaps Leah turned to the (now) ex once she found out she was pregnant. She wouldn't have wanted to go to her parents because she wouldn't want to disappoint or upset them (all MOO).
Perhaps the ex freaked out at this news and imagined the worst in terms of consequences. Perhaps the ex decided things were too unstable and unpredictable and so decided to remove the one uncontrollable variable. Perhaps the ex lured Leah with a promise of a future together.
Perhaps Leah was told that she and the ex would move away to start a new life together and that once his divorce was finalized and they were married and the baby was born that they could reappear and reunite with friends and family and all would be forgiven and forgotten and they could live happier ever after.
Perhaps Leah was instructed to turn off her locations on her regular phone (having previously been given a burner phone) on the night before her disappearance in preparation for their getaway. Perhaps they were to leave that night and Leah changed clothes, gave a false story regarding plans (to buy herself some getaway time) and took off to meet her lover. But maybe he was not able to meet her that evening, for whatever reason (wife stayed home when she had previously planned to be out that evening?). So maybe there was a quick change of plans and they would instead leave the next morning. Also, the morning would possibly buy them more time.
Perhaps the next morning the ex had a change of heart and didn't show. Perhaps Leah was distraught and threatened to tell someone or everyone - his wife, her parents, her brother, etc. Such a statement may have made him realize that his "problem"wasn't just going to go away. So he tells her okay, don't be upset, you're right, I'm coming.... then he meets her at the lake. Perhaps he then writes the rest of her story.
In my mind, this scenario fits all the evidence we have thus far -- and is also all MOO.
Okay, WSers, please pick this apart...
