Es regnet und die Kinder verbringen die Pause im Klassenraum. Jeder hat etwas dabei, um sich zu beschäftigen, aber alle wollen, dass Percy mit ihnen spielt. Percy möchte eigentlich lieber seinen Comic lesen. Da erzählt Frau Eule eine Geschichte: Percy und seine Freunde machen sich auf die Suche nach dem "Heiligen Gral". Dazu müssen sie als erstes den magischen Stein Merlins suchen und ihn am Rand des Heiligen Bachs ablegen.
It's raining in break time, so the friends are inside. Percy wants to read his comic, but his friends all want him to help them do the things they want to do. Miss Hoot sees that he can't say no to them... In Tiger Towers. Percy is really keen to go and find the Holy Grail. It's his main ambition. But each of his friends have something they'd love to find too - and because Percy doesn't like to say no, he's constantly distracted from his quest. He realises that he's never going to find the Holy Grail if he doesn't learn to say no - and part of it is getting the others...