School Friend #221

School Friend #221 is an anthology featuring three stories. "The Riding Mystery at Moorland School" follows Wendy Glynn, a new riding instructor whose team wins a school governor's prize, but the prize—an ancient picture revealing a secret passage—goes missing; Mr. Dawson and the girls investigate plots by Cyril Nokes to prevent Wendy's success, discovering Cyril and his accomplice hidden in a secret tunnel beneath the school. "Morna—Rebel of the Manor" by Hazel Armitage tells of a girl named Doreen who encounters the mysterious Morna Wellington on a bicycle; Doreen follows Morna and becomes entangled in intrigue involving an old mandarin named Ki-Ming, learning that Morna seeks a precious object guarded by the mandarin and must undertake a dangerous crossing of the moors. "Susie's Wonder Cruise" by Jane Preston depicts Susie organizing games for children aboard a ship, where she must locate the missing nephew of a passenger, Johnny Warren, who has mysteriously disappeared from the playroom.