When there is romantic mystery or friction in a series such as this one, marrying the characters is the kiss of death. I lost interest after the whole flirtation-avoidance dance ended - watching Kate Becket grin adoringly at Castle in nearly every shot of them together was too much to bear. Much of the humor inherent in that uncertain dynamic was also lost. It's really too bad, because they had a good thing with "Castle" and its characters who were appealing and fun to watch.