Franklin, the American bandit from the Wild West, has been travelling backwards and forwards in time, stealing famous inventors' ground-breaking creations and selling them on. From the steam engine to the television - nothing is safe. He has now arrived in Victorian London and plans to go to The Great Exhibition, hailed by Queen Victoria as containing “every conceivable invention”.

Will our time travelling detectives, Abby and Harrison, be able to catch up with Franklin before he strikes again? Or will they have to man the police desk for lost children and umbrellas?