Five go off to found an Utopia in a French forest, but, under the influence of the inaptly named Joy, the action soon becomes less Enid Blyton and much more the Marquis de Sade meets Lord of the Flies. Not for anyone worried about the behaviour of their young adolescents!
She was guilty of that, beyond doubt. Louis may have claimed that the facts behind her escape attempt remained unproven, but, as Joy pointed out, this was basically irrelevant. Isobel was guilty of what Rousseau called 'the greatest crime'.