Pittacus Lore books in order
11 books in the catalogue, about 71 hours of reading in all; the shortest takes 1 hour and the longest 9 hours.
1 series and 6 standalone books in the catalogue.
Lorien Legacies
8 books
I Am Number Four 8.1 h 
I Am Number Four: The Lost Files: Six's Legacy 2.4 h 
The Power of Six 7.5 h 
The Rise of Nine 6.6 h 
The Fall of Five 6.5 h The Revenge of Seven length not known
The Fate of Ten length not known
7 United As One length not known
