I can't say the summary of this book because it would spoil everything about the first two books. So if you haven't read this series yet I would not recommend the spoiler section.
I loved all the charachters, the storyline and the writing style, so I think this series has became my favorite series ever! I also love the fact that so many quotes and facts from other books were in this book as well, because the main character loves reading as well. I haven't read TMI yet, but I've heard that series is that good as TID, but I still really want to read TMI! (I still have to buy it so I'm waiting for my birthday in December). I recommend this trilogy to everyone oh and you can read this series before TMI if you want to.
Have you read The Infernal Devices series and what are your thoughts about the The Mortal Instruments series?