Locke & Key definitely has all the elements I've come to absolutely love and respect from Ms Derr's works. Sadly, because I've only read some short stories from her recently, I haven't really gotten a chance to appreciate it.
I love that this book, though it has three separate stories, is based in the same world with the same characters. I think partly the reason why I love this is because you kind of get a glimpse of what the characters are like before entering their head and story, so it makes the characters all the more endearing to you.
Like all her stories, the stories are so damn lovable (some infuriatingly so), their romances are funny, sweet and a treasure to read, and they leave you with this awesome afterglow which I've come to compare with the afterglow after sex. Or, after reading a good sex scene, that is, haha.