The series centres on three brothers, nicknamed Toughy (wants to be a soldier), Smarty (clever), and Mouse (likes cheese).

[1] After a while they discover that the island is home to the eccentric grasshopper expert Cornelius Button and his feisty housekeeper Lupus.

After making friends with their new neighbours, they join forces with them to defeat the unsavoury Doctor Hopper, who wants to destroy Button's reputation and seize Grasshopper Island.

He was also given Grasshopper Island by way of reward, and when the villainous Dr Hopper tries to have him removed, he must find another Button's Blue to keep his tenure.

He initially wants to stay with the boys, but soon leaves after finding the environment too hot and the terrain too taxing.

The Voices of Authority (all played by Tim Brooke-Taylor) A succession of overbearing (and mostly unpleasant) characters known to Toughy, Smarty and Mouse before they leave home.

They include a businessman who shouts at them for making too much noise, a matronly woman who forbids Toughy to talk with his mouth full, a barber who gives a reluctant Smarty a short back and sides because 'curls is for girls' and a grumpy taxi-driver who drives them to the docks.