There are six children in the Bastable family: Dora, Oswald, Dicky, Noel, Alice and H. O.

In the past, they were a happy family in a big, beautiful house. But now, their mother is dead and their father's business isn't good. The family needs money and the imaginative children want to help. They think of a lot of ingenious ideas to make money, but these aren't always practical.

Can they help their father, and become a happy family again?