Max's birthday party was supposed to be held outdoors, but the sudden rain kept everyone inside. When he, Erin, and April are exploring Max's attic while waiting on Erin's mom to come pick Erin and April up, they stumble across a hidden room containing an old mirror. When the light atop the mirror is turned on, whoever is standing in front of it vanishes--turned invisible!
That's strange enough, but when Max has been invisible for too long, he starts to feel odd, like the mirror is pulling him in. Could there be more to this mirror than meets (or doesn't meet) the eye?
The sixth book in R. L. Stine's Goosebumps series, Let's Get Invisible! offers a much more fantastical story than the previous book, The Curse of the Mummy's Tomb. Max is concerned about whether the mirror is really safe, but his friends only seem interested in competing to see who can stay invisible the longest, and his little brother, Lefty, only wants to use it to pull pranks.
Let's Get Invisible! is at least as well written as the previous book in the series, with a more interesting story. The characters didn't grab me as well as Gabe and Sari in The Curse of the Mummy's Tomb, but they're not bad--though I admit it took me a few pages to realize that the girl nicknamed 'Mouse' wasn't the shy one. That's what I get for making assumptions.
The idea of a world made up of our reflections--our 'cold' sides--is interesting, though it seems like, in Let's Get Invisible!, those reflections only came into being the first time the light on the mirror was turned on. It was pretty obvious that there was going to be some kind of going-through-the mirror happening--the emphasis on Zack's haircut being asymmetrical, and the presence of a left-handed character called Lefty are dead giveaways that the left-right distinction is going to be important. Though, I wonder, if they laid the mirror on the floor and stood on it, would their reflections come out upside-down? Nah, that'd just be stupid.
Let's Get Invisible! is a good book, with a different kind of horror than the usual monsters-and-danger kind. It doesn't seem to be available for the Kindle, but it's not hard to get it used, so you can still read it, if you like. Give it a try!