Jo is so excited! Her parents have agreed to let her host the Sleepover Squad to celebrate her win in the spelling bee! Jo loves to be organized, so she's busy making plenty of lists — like what kind of food she'll serve her friends and what games they'll play. She's even picked a special theme! But when the Squad starts acting strangely, Jo gets worried. It seems like her friends are keeping secrets from her.

Jo tries not to let their behavior hurt her feelings — after all, it's probably nothing. But she can't help but wonder: What if the girls don't want to come to her sleepover anymore? Or worse, what if they don't want to be friends with her at all?