Request #436 From Morgan

 I’m looking for a book I read in 2005 or 2006. It was either 5th or 6th grade. I only remember a very few vague details. There was a boy and his uncle (or grandpa) who is a scientist? The uncle takes them on a trip to another world/dimension/time? I remember them having an encounter with Medusa? And other creatures of the like, but I specifically remember medusa. If you could help me I would greatly appreciate it, this has plagued me for SO LONG. This book was one of my favorites as a ki