Milly and Molly remember their first day at school. It’s a wonder they ever became friends; they seem to be so different. Indeed, by the end of the day it’s hard to believe that they could ever become best friends. But thanks to their shared feelings for their cats, they soon find that they have much more in common. When Alf joins Milly and Molly’s school, he seems different from the other children. He likes different things and is proud of his difference. Unfortunately, Milly and Molly find it difficult to be friends with him, they don’t seem to have anything in common. But when Alf is subjected to bullying, Milly and Molly try extra hard to befriend Alf and discover that despite their differences, there is always common ground.

Milly and Molly pluck up the courage to camp out all night, way down the bottom of Milly’s backyard. Thanks to some naughty local boys, the girls think there could be bears in the garden and when night falls every noise and shadow frightens them. But they stick it out. Things come to a head when they see eyes glowing in the dark and something jumps on their sleeping bag!… but they need not have worried, it was just their cats, Marmalade and Tom Cat, wanting to go camping too. Milly and Molly start eating special breakfasts to feed their brains for the storytelling in Miss Blyth’s class. They eat extra nutritious and yummy muffins from Aunt Maude. But Humphrey isn’t eating breakfast at all, struggling even to stay awake in class. He’s not going to do very well in his storytelling unless Milly and Molly can get him to eat those muffins, but how will they overcome Humphrey’s fear of Aunt Maude?

Milly and Molly’s teacher is sad when her pet budgie dies. The girls buy her a new one, but the fun-loving bird they choose goes quiet as soon as they leave the Petshop. They can’t understand what’s wrong with the little fellow, until finally Milly and Molly return to the shop. The girls discover they have unwittingly separated the budgie from his mate; reunited, the birds are happy again. Milly and Molly chose another budgie to make their teacher happy, one who needs a friend. Its the annual Pet Day which will test the obedience of everyone’s animal. The two girls try hard to teach their cats to behave, but the cats’ instincts get the better of them on the day and Pet Day turns into a riot of animals… including a stinky skunk!

Milly and Molly’s class want to raise money to purchase musical instruments. They decide to make shirts and sell them. Alf’s Nan can’t afford material for Alf to make a shirt, so she sacrifices her own bed covering to provide the material. When Milly and Molly find out, they decide that the money they raise could go to a better cause and they make do with some homemade instruments. And Nan gets a patchwork quilt made from all the left over material from the class shirts. All the kids in Milly and Molly’s class decide to buy some expensive playground equipment, a jungle gym. They are going raise the funds by making and selling biscuits, each person in the class contributing their own skills. But the plan comes undone when not everyone wants to work together. As the deadline looms, it looks like they aren’t going to make the money they need. But Milly finds a way for everyone to co-operate. The class are rewarded with fun on their new Jungle Gym.

In the Gift, Miss Blythe sets Milly and Molly’s class the task of giving something to each of the lonely people in town. It must be special and show that the community does care. Milly and Molly help all their friends to find the right people to help and the right gifts for them, but discover there is no one left for them to give a gift to. In the end they get all the lonely people together, giving them with the best present of all: companionship. In Harry’s Mouse, Milly and Molly think they know all about looking after animals… until they promise to look after Harry’s Mouse while he goes on holidays. The mouse escapes more than once, causing havoc, hysteria and heartache, especially when the girls think Marmalade has had Harry’s mouse for dinner!

In Cat’s Alive, a happy event becomes a drama when Milly and Molly can’t find a home for the last kitten. Milly’s Dad threatens the worst, but the story ends happily when the lonely Ferryman takes on the last kitten, who becomes his faithful first mate Bosun. In Mr Limpy’s Vase, Milly and Molly try to help Mr Limpy with some chores, but thanks to the cats and Mr Limpy’s dog, and to some extent Milly and Molly’s forgetfulness, a precious vase is broken. Milly and Molly try to fix the vase without telling Mr Limpy but in the end have to own up to the accident and make amends to Mr Limpy.