October Ogre - Ron Roy, John Steven Gurney
If Calendar Mysteries is A to Z Mysteries for a younger audience, October Ogre is The Haunted Hotel for a younger audience. Once again, there's a spooky mystery at the Shangri-La Hotel in Green Lawn, and this time, Bradley, Brian, Nate, and Lucy are on the case instead of Dink, Josh, and Ruth Rose. The stakes of the mystery are suitably lower, given the difference between the ages (an age difference, I will point out, that is far less than the apparent difference in competence/maturity levels--make of that what you will); while Dink and his friends went ghost hunting and spying, Lucy and her friends are attending a Halloween party that gets a bit creepier than they anticipated.
 
Like the rest of the Calendar Mysteries books, it's a casual mystery with some pretty low stakes--which isn't to say that it isn't an entertaining read. I imagine that for the target audience, October Ogre, will come across as a fun, spooky story perfect for Halloween (though if your small child is already a well-read horror fan, they'll likely find the story tame). And if your child or student wants more, I definitely recommend checking out The Haunted Hotel, too.