"Don't touch – it's poisonous," thirteen-year-old Jess Ponder, the Schools' Secret Agency 'Double A-Star' agent, tells schoolmate and master of the forged sick-note, Leo Sleepwell, when he sees a trail of dried, gold saliva on the seal of an envelope. The letter it contained was sent to Jess by the notorious Nine-carat, aka 'The Man with the Golden Tongue'.

The head of the agency pulls Jess from the mission to locate Ms Higson, developer of the Plascrylics Aspitator, which could rid the world of its discarded plastic. Jess is just too valuable to risk losing. However, ignoring advice to return to school and improve her algebra, Jess persuades Leo to accompany her to Italy, then Hong Kong, to track down Nine-carat and thwart his dastardly plan to use the Plascrylics Aspitator as a weapon.

So begins a fast-paced, James Bond-inspired adventure where Jess must contend with not only Nine-carat's evil intentions, but also his mischievous monkey, a martial arts-mad man in flares, anxiety-inducing apparatus, and Leo's gargantuan appetite.