Saw it yesterday, and loved it. It’s been a year since I read the book, so some of the details have faded, but here’s my thoughts on some of the problems some of you have mentioned.
The character of Greta may have been all sympathetic and friendly, but she and her boyfriend are also drifter-types living on the edge, looking for any fast cash and only loyal to each other. Sure she may have been friendly, but the sight of all that cash was the clincher. I don’t think they recognized Amy, but they did recognize a fellow on-the-edge soul who wasn’t going to be able to go to the police about being robbed. And the movie didn’t change Amy’s appearance as much as she did in the book.
The origin of the baby was mentioned in two fast throwaway lines between Nick and Amy when she says she’s pregnant…he says something about the letter about the clinic saying the sample would be destroyed if they didn’t tell them otherwise, and Amy replies that she contacted the clinic and told them to NOT destroy it, but threw the letter away so Nick would find it and think the sample was lost…then when she reappeared, she had a way to get pregnant by him even though he refused to sleep with her.
Keep in mind the whole reappearance thing was only thought up when she realized that Desi wasn’t going to just give her money and keep quiet about her…he was truly obsessed with her, and was going to protect her in a very luxurious prison, though he didn’t consider it one…he was just keeping her secret. It was only after she realized how trapped she would be that she formulated a plan to eliminate the one person who knew she hadn’t been kidnapped by making him the kidnapper. When she saw the signals from Nick in the interview that he had figured out she was alive…the reference to being “taken to the woodshed” and the touching of his chin in their “tell no lies” secret sign, she hatched a plan to return home in the only way she could that would ensure no one would go to jail, and turn her into a heroic survivor…with a book deal and options for a film about her ordeal. She knew Nick now hated her guts, but she knew how to trap him to her side and still be protected from him.
As to the lack of a wound to explain the blood…well, in her original plan, her body would either never be found, or found after being in the water a long time. The fact that she had to retro-fit Desi into the original plot meant there would be some inconsistencies she couldn’t account for. And I’m not sure the whole “continuing to fuck Desi while he’s dying” thing is obvious, as someone thought it was. I didn’t get that impression at all. Those movements could be interpreted as struggling to get disentangled, though I wasn’t watching her hips as much as watching Desi’s face, so maybe what I saw as “get this guy out of me” moves were something creepier.
As unsympathetic a character as Nick is, we have to feel for him at the end, as he realizes he’s trapped (is she even really pregnant at this point, or is that a lie, too, but he knows she has the means to GET pregnant? I can’t remember from the book) for life by someone who will from now on always get her way. And wasn’t that really the source of most of Amy’s insanity…that once she stopped getting her way in life…when she had to give her parents the money that would have kept her and Nick afloat until they could start new careers, the fact that she had no say in moving to Missouri to care for Nick’s mom, that she didn’t have a say in the bar that Nick guilted her into financing…once she had no control over her life, she spun completely out of control and decided Nick had to pay for her unhappiness. I think the ending is more satisfying than having her machinations unspooled…not from a sense of justice standpoint, but from a “this is what makes this movie a true horror story” standpoint.