Remember the Green Glass Door riddle? This challenge is exactly that- to complete this challenge read books that include a word with double letters in their title. 
This challenge has no time limit, so there is no rush to get this completed. 

Some thoughts to make this challenge, well more challenging: 
-Only include titles that have a double letter vowel (i.e. door, been, etc,)
-Only include titles that have a double letter consonant (i.e., battle, terrific, etc.)
-Don't repeat words with double letters for more than 1 prompt 

*Extra challenging: 
-Only include titles with more than 1 word with a double letter  (ex. Assistant to the Villain)
-Work through the alphabet using double letters 

For the sake of this challenge, a double number (i.e., 11, 22, 33...) will count!

Happy reading!