The Tamakis really know how to tug at those nostalgia strings. TOS is a glimpse into the summer vacation of a young girl and her family. There are no zany mishaps and no unnecessary drama, just regular old family and preteen issues. And yet, it's fascinating. The story, told from the girl's point of view as if in a journal, is relatable. We've all been 11 years old before, and we've all wanted to understand the world around us. The story isn't anything new, but the result of the way it's told is. It's a lovely read for a rainy day.
TOS is written for young adults, so there's nothing too mature for anyone 13 and up. As with The Wrenchies, I'd recommend being older than the main character to read it, just to get that whole nostalgia factor. Or, as I do with many books, read it once, put it down, and read it again in a few years to understand it better. Books are made for cracking open several times. Not Kindles, though. Do not crack your Kindle.