I can remember the ending and it was fairly normal by SH standards.
SPOILERS SPOILERS SPOILERS
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Gaby solves the case.
Tim went back to Francine when she had her stroke, not to take care of her but to torture her day after day by telling her how awful she was, how much he hated her and how they all laughed at her behind her back.
Kerry and Dan wrote the notes for the same reason, sitting by her bed to write them and then stuffing them under her mattress without a word so she had to lie on them and wonder what they said.
Lauren realised this and she murdered Francine to save her. Apparently Francine was her best friend and Lauren was upset that she was trapped and being abused so badly, but as Gaby said so often, Lauren was thick and she didn't know how to tell anybody about it so she thought killing her was best. 
Lauren also murdered her husband Jason later on, because he attacked Gaby and because he was abusive. Lauren's father took the blame but they all knew it was her really.
Kerry was in love with Tim all along and sent the valentine card that split him and Gaby up. Dan knows but doesn't care because Kerry isn't Tim's type and he loves him too in a non-romantic way.
Dan and Kerry disappear with Lauren so she isn't prosecuted.
Gaby still loves Tim and once he's out of prison they go to Switzerland to solve the mystery of his dream where Francine tries to kill him with a handbag. Turns out the white room was a mountain, the handbag was a cable car and she never tried to kill him, his subconscious just thought he shouldn't marry her.
But, Gaby leaves him there and returns without him because she's upset he went back to Francine and although she still loves him she wants him to get a grip and stop being so useless.
SH needs to write another book in which Waterhouse and Zailer explain what everyone saw in such a wet lettuce as Tim. Because I really don't get it, he was completely useless, spineless and bland in every way.
But at least she didn't write three endings that made no sense, like she did in Lasting Damage.