Books in the Jeffrey the Third Grade Detective series

What’s Christmas without Max?   Jeffrey Becker is looking forward to the greatest Christmas ever. Nothing beats spending the holidays with his best friend, Max. Especially when Max happens to be a mischief-loving 1950s ghost.   But before vacation begins, Jeffrey and Max argue, and Max disappears—maybe for good! To make things worse, it looks like Jeffrey will have to spend Christmas with—yuck!—his obnoxious cousins Jonathan and Wendy. Why bother to celebrate at all? Jeffrey needs his ghostly friend to come back, but there’s no sign of the stubborn Max. Will Max ever return?

When Ricky Reyes dares Jeffrey to get a bloody dagger out of the old McGyver house on Halloween night, Jeffrey is counting on Max, his ghostly friend, to help him.