The Miraculous Mellops concerns the Mellop family. Father Bill Mellop runs a nursery, aided by his children - Samantha, Michael, Jason and his sister Jocelyn. After the recent death of their mother, Jocelyn acts as housekeeper. A strange star arrives from space and confers uncanny powers on the children and their surroundings. The visitors from outer space complicate the struggle the Mellops already have on their hands with neighbour Bernie Dump, who wants to take over the land which houses the nursery.