The Hardy Boys Secret File #7 The Disappearing Dog by Franklin W. Dixon illustrated by Scott Buroughs*

Frank and Joe's classmate, Max, claims he can make anything disappear.  But when a prized dog keeps vanishing, Frank and Joe decide to investigate.
My second grader loves this series.  He read this book to himself.
*Highly recommend series.
Guided Reading Level: N (third grade)
If I taught 2nd-3rd grade, I would purchase this series for my classroom library.