In the first chapter, we are introduced to the characters as they create and decorate buildings out of cardboard. As they do so, we come to learn their different personalities. Freddie is impetuous, Flossie enthusiastic, Nan more cautious and rational, while Bert seems to be a more extroverted version of Nan.

The second chapter takes place outdoors, as the twins play with their friends. A medical crisis occurs from which Nan learns a lesson, and we also meet the neighborhood bully for the first time.

In Chapter Three, a snowball fight between Bert and Danny Rugg ends in disaster.

In Chapter Four, Bert talks to Danny and learns that even if he wants to tell an adult about what happened, he can't.

In this episode, Bert sees a ghost. Although his mother says he must have had a nightmare, he's convinced that he really did see something. Later in the afternoon, he and Nan go to the neighborhood sledding hill. They race their sled against Charlie Mason's, and have fun doing it. But as soon as Danny Rugg comes, the day ends very badly for Bert.

In Chapter Seven, Diana pulls Freddy out from under the snow before he suffocates, and everyone is relieved. Immediately, Freddy begins to build it again, although this time he's under the supervision of Nan and Diana. Later that day, Burt and his friends conclude the snowball fight to everyone's great satisfaction.

In Chapter Eight, Nan and he head off to the lake to ice skate with their friends. First they watch a man who had won a skating award doing fancy tricks, then they separate to play with their friends. While Nan plays tag with hers, Bert and his friends play a game called Snap the Whip. In this game, Bert crashes into an unfriendly man, then he ends his day at the pond by deciding to build an ice boat with Charlie Mason.

In Chapter Nine, Christmas is coming, and the stores are filled with toys and presents. Freddie and Flossy go to a big store with their mother. While she's shopping for a rug, Freddie wanders all over the store and ends up getting locked in a room with no other people, except one special little friend.

In Chapter Ten, the family contacts the police to help them find Freddie and everyone is very worried. Eventually, the search is called off--but I'm not going to spoil it by telling what happens!

In this episode, Nan and Burt go out on the ice boat that Burt made and end up battling a storm. Bruised, tired, and hungry they attempt to walk the six miles home. When they hear a dog barking through the snow, they begin to get worried. When they see it burst out of the night, headed straight toward them, they get even more concerned!

In Chapter 13, Nan supervises all the kids in making a surprise cake for their mother. Needless to say, not all goes as planned, and a good deal of their afternoon is spent in clean up.

In Chapter 14, the twins pool their money to buy Christmas gifts, talk about what they hoped to get, and then the family celebrates the big day together.

In this episode, all of the twins go to a party at Grace Levine's house. They have an absolutely wonderful time playing games, watching funny movies, eating ice cream in different shapes, and finding presents folded into their chocolate bonbons.

In the last chapter, the Bobbsey Family heads off in their sleigh to visit their friends in the country. Burt and his friend Bob ride in their small sleigh to a nearby lake where they watch a hockey game. On the way home, another boy challenges them to a race. Burt has a moment of fear because he knows that his friend's horse used to be a racehorse and is capable of running at great speed. The chapter ends just before anything bad happens, but I think we can all guess that something will indeed happen!