I found the final book in the trilogy to be much better than the 2nd. Grossman's world-building continues to be fantastic with additional settings and a newly introduced main character. Where this book continues to fail is having likeable protagonists. Elliott's character growth has made him probably the most likeable of the original characters and the new introduction, Plum, is also fun to follow. This book holds two separate stories (In Fillory and on Earth) which then intertwine about 3/4s of the way.

Most disappointing I found was the ending. It gives you so much just to take it away. And there is no real ending for most of the characters and you're left to assume what they will do going forward. If you've made it this far, definitely worth the read to finish up the trilogy.