Class 3 from Hampstead Primary School are off on a school trip to Paris. First of all, Miss Parker the new supply teacher isn't meeting them till the bus gets to the ferry. She really is a bit odd. Is their bus being followed? Who is the strange bearded man? When the world famous Mona Lisa
painting is stolen from the Louvre, the children of Class 3 are on the case at once.
Class 3 of Hampstead Primary School are off on a school trip to Paris! Morgan is the first to spot the bearded man in the black Citroen car, cruising behind their school bus, and feels sure he is following them. The plot thickens when a second mysterious bearded man appears on the ferry boat, Soon Class 3 find themselves entangled with a group of art thieves intent upon stealing the Mona Lisa . . . !