The plot centres around Jack Green, an environmentalist and undercover agent for MI5, who with his family are on a mission to save the planet.
Jack's archenemy was a criminal known only as "the Vixen" who would come up with diabolical schemes to rule the world.
All Tied Up Uncle Jack accidentally gets hold of a formula for a lethal new gas being developed by the GasChem company, but MI5, the Russians and the Americans are after it and all request help from the World's smartest criminal, known only as the Vixen.
Countdown Uncle Jack and his sister's family visit his cousin and his daughter, Tammy, in Scotland only to find that he has disappeared since he went fishing in his boat at Loch Noch and Tammy has been left at home on her own.
Jack discovers that the marine base at the Loch is hiding something after also seeing a radioactive material that keeps appearing everywhere that ties in with the mystery of his cousin's disappearance.
Off With His Head When Uncle Jack visits Kate at her new school, he discovers the weather around Brimley Crompton is changing from one extreme to another with heat waves, sudden blustery winds and rain, as if someone is controlling the weather.
Uncle Jack travels to Egypt with his niece Helen to find the lost treasure of Queen Cleopatra, but a mummy seems to be guarding it.