The Chalet School and the Island
After a bout of mystery illnesses, the drains at Plas Howell, the school's home, need to be seen to. As the work may take up to a year, a new home must be found. After turning down several unsuitable offers, an offer finally comes that suits everyone - The Big House on St Briavel's, an island off the Welsh coast. Meanwhile, Dr Jem Russell has taken most of his family, with the addition of Margot Maynard, to a conference in Canada.
For the most part, the school is excited by the move and all the changes it will bring, especially the prospect of water sports. Unfortunately, Annis Lovell, after a term at the school, has still not settled down, and sets out to cause some trouble. Annis declares that she will make Bill and the Abbess thankful to be rid of her come the end of the term, and sets out to fulfill her threat. She is isolated from the rest of the school after refusing to apologise to Mademoiselle Lachenais for rudeness.
There is another discontented soul - Cherry Christy resents a school coming to live in her home, while she and her family must move. Her sister Dicky, however settles happily in the school. The school meet Kester Bellever and visit the birds on his island. Feeling that her Aunt Margaret resents looking after her, Annis Lovell decides to run away and is soon in great danger.
contributed by Lorraine O'Donnell, Sligo, Ireland__ working from a paperback edition
As the link suggests, it gives more of the story - without, of course
giving everything away!