Bientôt l'œuvre, dont la cote ne cesse de monter, va susciter la convoitise de certains de ses proches. Témoin des affrontements qui opposent Olivia, Nancy et Noël, Pénélope découvre le vrai visage de ses trois enfants. Ce regain d'intérêt pour le tableau provoque aussi chez elle un retour sur son passé : sa jeunesse bohème, sa rencontre avec Ambroise, son futur mari, puis avec Richard... La vie de la digne vieille dame révèle alors des secrets insoupçonnés.
Artist's daughter Penelope Keeling can look back on a full and varied life: a Bohemian childhood in London and Cornwall, an unhappy wartime marriage, and the one man she truly loved. She has brought up three children - and learned to accept them as they are.
Yet she is far too energetic and independent to settle sweetly into pensioned-off old-age. And when she discovers that her most treasured possession, her father's painting, The Shell Seekers, is now worth a small fortune, it is Penelope who must make the decisions that will determine whether her family can continue to survive as a family, or be split apart.