Books like I Am Mordred
Nancy Springer
I Am Mordred is 184 pages, about 3 hours 22 minutes at 250 words a minute.
7 books to read next
How long each takes
The Winter Prince 3.7 h 
Crown's Game 7.9 h 
Once & Future 6.8 h 
King Arthur and His Knights of the Round Table 5.6 h 
Doomed Queen Anne 4.2 h 
Snow Spider 2.9 h 
Listen to the Moon 6.5 h Bar height shows length. Estimated at 250 words a minute.