The school janitor knows more than he's willing to say, so it's up to Max, Liz, and Chen to figure out what's got him so on edge in Book 6 of the Code Breakers series.

After a series of unexplained messes throughout the school, Mr. Fox, the school janitor, is at his wit's end. Our code-cracking trio are looking to help. Can they discover what's behind it all? And what role Miss Graph, the librarian and leader of the Code Breakers Club, has to play in it?

This decodable chapter book lets upper elementary readers build fluency with R-controlled vowels and diphthongs while unraveling this page-turning mystery. The series includes accessible, dyslexia-friendly font and takes readers through a systematic sequence of skills.