Underwear Fairy, Oona Brambelgoop, and her friends Horace and Lucy (the Tooth Fairy) are trying their hardest to prove they are responsible citizens of Fairydom, and catching the culprit of the great glitterberry warehouse theft is the perfect way to do it. But when the leprechaun gold Lucy has given kids for their teeth also goes missing AND she starts to lose her magic, the friends realize this must be about more than just berries. It turns out Lucy has been manipulating magic to get more gold and the leprechauns are not happy! Oona will have to use all the creativity she can muster to stand up to the leprechauns and save Lucy's job. Can she restore harmony between the two magical communities before Lucy loses her magic for good?