Bored in the summer holidays, two children wish for a real adventure. The discovery of an old-fashioned wireless set provides the fulfilment of their wish.
Two young friends, Tim and Tammy, wish for an adventure to ease their boredom during the long summer holidays. When they find an old wireless set hidden in some bushes, Tim recognizes it as having belonged to his recently deceased grandfather. But the old man had modified it, and when the children switch it on, instead of tuning into a radio station, it tunes them into a different world. At first it looks like our world, but then many differences appear—dress codes, technology, dialect, etc. The children discover that everything is done in eights, hence the name ‘Octolia’ for this world. Befriended by the Middleton family, Tim and Tammy learn about the Octolians’ form of government, style of worship and other strange customs Tim realizes that the direction of time in Octolia is different from that in his own world—two weeks forward in Octolia is one day back in our world. Before they return to their own world, the children are launched on a daring project, which continues in Book Two of the trilogy.