The Tooth Fairy and The Sugar Plum Pixie

Ollie and Grace hate brushing their teeth, and plan to trick the tooth fairies by creating fake teeth out of sugar cubes and putting them under their pillows. But when they get found out they are marched to the Royal Mint to face the Chief Tooth Fairy - who tells them all about the dastardly Sugarplum Pixies, and she also likes to play nasty tricks...