For new girl Darrell Rivers, there are friends to be made, pranks to be played and fun to be had at Malory Towers in Enid Blyton's best-loved boarding school series. In book three, there are lots of new students, including sophisticated Zerelda from America. This year, not only the girls face challenges - Bill's poor horse, Thunder, suffers from collic. Will Zerelda and Darrell become friends, and will Thunder survive?