If there's a problem in school, there's no substitute for the super-sleuthing, world-saving substitute teachers of the S.O.S.! This is the sixth book of this hilarious, highly illustrated early chapter book series.

It's Field Day! Milton Worthy is Room 311B's team captain and ready to lead the second-grade team to victory.

Little does he know, his classroom's pet ferret is hatching yet another sinister scheme to conquer the world. Will Milton be able to save the day before his own dreams of schoolyard victory are squashed?

HarperChapters build confident readers one chapter at a time! With short, fast-paced books, art on every page, and milestone markers at the end of every chapter, they're the perfect next step for fans of I Can Read!