Family is all-important to Isabel. Her parents have an idyllic marriage, and she has tried hard to make her own the same. But all pretence is shattered when her husband leaves her, soon followed by the death of her father. Then her mother confides in her: behind her parents' apparently happy marriage was a secret kept for more than three decades. Staggered by the revelation, Isabel is desperate to tell her sister, Grace, and her brothers, Rick and George. But her mother makes her promise to stay silent, and 'family-first' Isabel is left torn, with a dangerous secret to tell.