At first I didn’t quiet “get” why the disappearance of the grandfather didn’t produce more trauma than it appeared to…then “DAH”… I read that the book is written for 9-12 year olds… then it began to make a lot more sense and I started to read it as I would have if I was 12 years olds. Believe me folks…that nearly qualifies for ancient history:) Mia was a wonderful character. I’ve never read this author before but was impressed with her making the writing like it had been penned by a real kid. Mia’s relationship with her grandma starts off on a rather strained note…but they soon grow closer as they are both worried about grandpa. The theme of time travel was also done very well. Since no one has ever done it except in books like this there are usually some questions the reader will have about the logic…but I could find no real glaring holes or contradictions …but then if I was 12 years old I probably wouldn’t be looking for this. Good book and well worth the time to read. I’m not going to tell you how the missing grandpa mystery turns out. That would ruin the whole adventure for you if you choose to take a trip through time. ( )