The teacher on Euphoria Island is sick so Kate agrees to fill in -- the only problem is she doesn't know what to each! That's why she asks Alex to come to class and give a talk to the children -- but Alex is worried that he isn't clever enough to teach. That's why he goes to the library and takes out all the books he can find -- nothing can go wrong if he just sticks to what's in the books when he's teaching class, can it?