Books like The Lightning Thief
Robert Venditti, Rick Riordan
The Lightning Thief is 128 pages, about 2 hours 21 minutes at 250 words a minute.
12 books to read next
How long each takes
Percy Jackson & the Olympians 2.9 h 
The Sea of Monsters 5.2 h 
Zeus 1.5 h 
The Battle of the Labyrinth 6.8 h 
The Son of Neptune 9.4 h 
The Mark of Athena 10.7 h 
House of Hades 11.0 h 
The Blood of Olympus 9.6 h 
The Odyssey 4.7 h 
Abandon 5.6 h 
The Demigod Files 2.9 h 
Awaken 6.4 h Bar height shows length. Estimated at 250 words a minute.