Every Monday, Mabel wakes up early and peeks out her window to make sure she didn't miss the one thing she's been looking forward to for a whole week. She drags her chair down the hallway, past her big sister and Mom and Dad, and out the door, and then she waits. What is Mabel waiting for every Monday? According to Mabel, it's the best thing in the world. But no one else seems to understand ... yet.