Essentially it’s a book about being good, while acknowledging that there’s a time to let your fiercer side out.  After being good all summer, Millie’s mom tells her she can have a sleep out in the backyard.  She’s full of plans, knowing just how she wants it to go, but of course things don’t go all as she plans.  Throughout the story, Millie works to keep her fierce in until something in the dark outside her tent threatens to ruin her sleep out, so Millie unleashes her fierce to venture out to protect her friends…from what turns out to be the neighbor’s dog.  It’s fine, but is it just terribly old-fashioned of me to find it sad that watching movies on a tablet seems to be part of a modern sleep out?