A way to have the revenge ending (and make it realistic) -

This is, of course, IMHO:

Why didn't Halle try to tell other 911 operators or her police bf that she recognized the sound, and have them not take her seriously? THEN we have a more plausible reason for her to go on her own. Like, she could have tried to explain it to her boss, or her boyfriend (or another cop. ANY other cop), and have them tell her she's too emotionally connected to the case or something. She could even have gone home, had the source of the sound "dawn" on her (they could have shown her unable to sleep, or having a weird quick dream nagging her subconscious), try to contact the police over the phone, then take off on her own on a mission to save the girl. No, she just cavalierly sets off ALONE with NO WEAPON and tries to resolve things herself. I mean, at least she could have brought a weapon - with this idea, she could have just had a hunch and grabbed a tire iron or something and found it wasn't there, or dropped it in the dark when she found she was correct. She could also have tried to go up the ladder to call the police once she finds the girl/escapes the secret room, THEN if she dropped it, of course she'd have to go back down. Instead of just telling the killer what they were going to do, she could have smashed her phone in front of him, or shown it was smashed in the fall and told him she couldn't call for help even if she wanted to (which, of course, she didn't at that point). She could have said they'd "forgotten" where the trapdoor leading down to it was (I mean, she could have told the police that). I get a strong feeling test audiences caused the ending to be changed drastically from what was originally planned.

I still rate this movie a 5.5, but I was horribly disappointed. I love Brad Anderson's other movies, even The Vanishing on 7th Street which I know didn't receive the best reviews. This is the first movie I've put below a 7.5.

They're coming to get you, Barbara!