Philippa's Secret - The Secret of Blanch Lake

What was Denise up to when she stormed out at the end of a lesson and asked her cousin for a cigarette? Surely a twelve year old wasn't allowed to smoke on school premises even at boarding school. Then Ivy Friend and Eleanor Barnes had a fight. Poor Miss Roberts had to sort them out and if that wasn't all who was the fellow who Pippa and Terry found after he had taken a spliff and was tied up...