The Big Break Detectives are three friends, Danny Sullivan, Cait Conway, and her somewhat eccentric twin brother Little Tom, who attend Saint Agatha's National School in a leafy city suburb.
They run a detective agency during their school big break -- they advertise in the local newsagent window and operate from their secret headquarters in a forgotten sub-basement, full of obsolete computers, dusty and forlorn science projects and defunct office equipment, underneath the school.
As their lunch break is only 30 minutes long, they only have this half hour to escape from the school, solve the mystery, and return unnoticed before the bell rings again signaling the end of school break and the end of their adventure.
The Casebook, "written" in typically offbeat style by Little Tom, who has filled the pages with kooky asides and his own cartoons, features four stories full of humour and surprising twists.
