While Inkheart happens in our world and can stand as a complete story, its sequel Inkspell and conclusion Inkdeath both happen in the magical realm of Inkworld and are written as one continuous story. This is the first time the readers get to see Inkworld and it is a richly imagined world comparable to Hogwarts that is a treat to the reader's imagination.
In Inkspell, Dustfinger finally gets his wish when Orpheus reads him back into Inkheart. Determined to follow him, Farid gets Meggie to read him into the book and she goes with him as well. Worried about their daughter, Mo and Resa get Orpheus to read them into the book, too, but sadly along with Mortola and Basta, villains from the previous book. Now in Inkworld, Mortola and Basta are determined to get rid of Mo so Meggie finds Fenoglio, the author of Inkheart, who has settled into Inkworld to try to save him.
The story makes the phrase "The pen is mightier than the sword" literally true because Meggie saves Mo by getting Feneglio to write new lines into the story to change the course of events.
Characters. I thought that the leading characters of Mo and Elinor were well developed. I would like to think that Meggie has matured already since the previous book, however what she does at the start of the book was too impulsive for a 13-year-old, which was to follow Farid into Inkworld after what she and Mo had to go through just to get Resa back. It was as if she didn't think through the consequences. The whole story of Inkspell and then Inkdeath is sparked off by this event so perhaps it was Funke's way of getting the story started. Then I found too many side characters and creatures which made the story sometimes a little hard to follow, but perhaps it was Funke's way of making Inkworld as rich and real as possible.
Plot. Just like Inkheart, I found the plot to be too long and circular, instead of being a single linear one that slowly builds up to a climax. There were a lot of unnecessary descriptions and scenes that didn't serve to add to or build up the plot.
I also found the events to be a little hard to follow at times. Perhaps it was because of a lack in appropriate transitions or segues. I.e. Suddenly one of the characters you didn't know was in the scene says something and you think, huh, did i miss something? Or perhaps it was just 'lost in translation' from the original German.
But towards the end i think the pace picked up to a very good climax. The story ends hanging, making me want to get my hands onto the 3rd book as soon as possible!