Christmas is coming and Charlie and Lola have received an advent calendar to help them keep track. The calendar has a flap to lo open for each day leading up until Christmas. At school, they find that many of their friends have received the same calendar, so they trade stories of what things they found underneath the flaps. Charlie and Lola also get ready for Christmas, discussing wanted gifts, making cards, and writing letters. On Christmas Eve, Lola discovers something disturbing --- the flap for Christmas has disappeared from the calendar. The two go inside the calendar to find out what happened with Christmas.

It is the beginning of Autumn term at school, and Lola finds that everything is different. She and Lotta have new sitting places, she has a new teacher, the school smells funny, and the leaves have fallen off of her favourite tree. Meanwhile, Charlie and Marv create a time capsule for the Autumn Fair.