So the Mr Knell tell her she has to steal heartbeats in order to keep going. She goes on and lives for 150 years. She kills Jack the ripper and kills a boy who she claims she loves with all her soul and then she gives her last heart beat to a dying man with cancer.
And after that I won't give away the ending put I will say that I was royally pissed off. Like ROYALLY PISSED! I feel like I wasted 7 hours of my life on a depressing book that could have just been happy if she would have stopped bitching about something that is inevitable.