The young spies are called upon to investigate when they hear that the normally peace-loving Prime Minister is on the verge of declaring World War III. Going undercover, Daisy finds that the PM has been replaced by a cybernetic clone.

The Grand Master, leader of the Secret Kriminal Underground League (S.K.U.L.) threatens to freeze the world unless everyone submits to his rule.

When zombies start ransacking music stores, MI9 suspects that a boy band named Crush is responsible, so Daisy again goes undercover to investigate.

Everyone is in the dark as freak power outages sweep Britain.

When a hacker called The Worm takes control of Britain's space defence system and leaves the country vulnerable to attack, Stewart must employ his computer skills to the max.

When a teen working for the CIA joins the team, Blane's jealousy causes him to take a crazy risk.

A wannabe SKUL member, after overhearing an MI9 meeting, thinks that St. Hope's teachers are the agents and sends in bugged animals to spy on them. Okay, nothing much to worry about... until a truth serum dart accidentally hits Daisy.

A former beautician's youth potion ends up turning the school's teens into toddlers.

When a teen scientist invents a method of disarming missiles that could make the army obsolete, he is kidnapped by a war-mongering general.

The teen spies defy their superiors to help an extraterrestrial fugitive.

At an award ceremony for M.I. 9, the world's greatest illusionist makes the President of the United States disappear - permanently.

A bumbling inventor's Artificial Intelligence unit tries too hard to enforce the school rules.

When a fashion designer's green logo mysteriously begins appearing on kids' skin, Daisy and Rose go undercover to investigate the House of Ferrago as fashion models.

Britain's young people are laid low by a strange sleeping sickness.

The team investigates when their schoolmate Lenny becomes the latest one arrested in a new wave of inexplicable crimes by previously honest kids.

The high school spies become concerned when a Member of Parliament proposes sending misbehaving British children to a remote island.

A new Cold War is in the making, but this time it's the Grandmaster's plan to give everyone the flu.

It's Daisy's worst nightmare when a plague of head lice hits the school, and turns the kids into master criminals.

The high school spies are amazed to discover that they have competition -- there is another team of young people working for MI9.

The world's most famous diamonds are being stolen, and the team suspects the captain of the all-England football team.

A new invisible spy plane is stolen by a mysterious unknown pilot.

Plants rise up and attack anti-green targets, so Blane goes into action.

The government is powerless to stop an asteroid that is hurtling through space toward the Earth. Looks like it's up to our heroes from MI-9 to save the world.