Book details
Lets Get Invisible!
Goosebumps, 1993 by R.L. Stine
on Goodreads (11,789)
Description
On Max's birthday, he finds a sort of magic mirror in the attic. It can make him become invisible. So Max and his friends start playing 'now you see me, now you don't.' Until Max realizes that he is losing control. Staying invisible a little too long. It's getting harder to come back. Getting invisible is turning into a dangerous game.