After their dreams of starting a family are crushed, Philippa and her husband Marco need a fresh start. Focusing on repairing the crumbling walls and leaking roof of the Cotswolds house they impulsively bought seems easier work than repairing their relationship. When Philippa finds a hidden memorial hidden deep in the garden, the discovery only pushes them further apart. But as Philippa determines to uncover the truth behind the memorial, could the secrets it reveals be the key to finally putting their heartbreak to rest?

1933. Hannah Snow is fleeing her unhappy marriage to an MP when she finds herself in a small hotel on the banks of Loch Ness. But when a monster is spotted in the depths of the waters, the press descends – and Hannah finds her hiding place is discovered. Someone has been looking for Hannah, and when they find her events will take a devastating turn. Present day. True crime podcaster Scarlett finds herself intrigued by the mystery of Hannah Snow, wife of a promising government minister who disappeared in 1933 – just months before her husband also went missing, presumed dead.

December 1941: Evacuated from the threat of German bombs, sisters Amelie and Mireille have grown up under the storm clouds of war. Now they have joined the fight against Hitler, with Amelie training as a nurse to save wounded soldiers, and Mireille enlisted to help the Air Force wage war in the skies over Europe. But as each sister fights for peace, they are still haunted by the memory of their missing sister who was snatched away from them at the beginning of the war.

1912. As the steamship Carpathia takes the survivors of the Titanic to New York, a woman desperately searches the decks for her baby, thrust into the arms of another passenger as a lifeboat left, and now nowhere to be found. 2022. When archivist Jackie finds a notebook containing the stories of women saved by the Carpathia amongst an auction lot, she uncovers the story of a missing baby, a mysterious silver bracelet, and a journalist determined to share the truth with the world.

London, 1940. When nurse Elsie offers to send a reassuring letter to the family of a patient, she has an idea. She begins a book of last letters: messages to be sent on to wounded soldiers’ loved ones should the very worst come to pass so that no one is left without a final goodbye. London, present day. Stephanie has a lot of people she’d like to speak to: her estranged brother, to whom her last words were in anger; her nan, whose dementia means she is only occasionally lucid enough to talk.

It’s 1916 and, as war rages in Europe, Gráinne leaves her job in a department store to join Countess Markiewicz’s revolutionary efforts. It is a decision which will change her life forever. A rebellion is brewing, and as Dublin’s streets become a battleground, Gráinne soon discovers the personal cost of fighting for what you believe in. Decades on, student Nicky is recovering from a break-up when a research project leads her to her great-grandmother’s experiences in revolutionary Ireland.

Phoebe is a VAD at a Base Hospital in Étaples, France, treating men who’ve served at the Front. Their courage and resilience inspires her, and though she’s meant to keep her distance, Captain Archie Bailey soon captivates her heart. Her younger sister Celia is a nurse at a POW camp on the island of Jersey. These men fight for the forces that bombed her brother and parents, but long hours spent healing them shows her they aren’t the monsters she expected.

When Maggie’s new job takes her from bombed-out London to grand Snowden Hall in the Cotswolds, she’s apprehensive but determined to do her bit for the war effort. She’s also keeping a secret, one she knows would turn opinion against her. Her mother is German: Maggie is related to the enemy. Then her evacuee sister sends her a worrying letter, missing the code they agreed Violet would use to confirm everything was well, and Maggie’s heart sinks.

Pearl has given up on her dreams of being a journalist after being denied a promotion because of her gender. Joining the WAAF as a radio telephone operator for Bomber Command, Pearl's new job at RAF Fenthorpe serves two purposes – providing an income for her grandmother, and keeping a close eye on her younger sister, Thea, an instrument repairer at another Lincolnshire bomber station.

Claire has always had a special bond with her aunt Margaret, but she’s astonished when Margaret suddenly begins talking about a friend called Agnes, who Margaret met working as a WAAF in World War 2 – a past Claire had no idea about. Margaret and Agnes were best friends until Agnes started acting strangely, becoming secretive and distant. Then one morning, Agnes vanished and never returned home, leaving Margaret distraught. Claire promises to delve back into the past and help discover what happened to Agnes. 

1942, Warsaw. Young Zofia finds herself leading a double life when she is enlisted to help the fearless Irena Sendler save hundreds of Jewish children from the Warsaw Ghetto. Every night, Zofia risks her life to shepherd the children to safety. But when the worst happens, she is forced to make her riskiest journey yet to keep Irena’s mission alive.

Emily Moon lives with her mother in an inn on a clifftop in the darkest reaches of Cornwall. After her father mysteriously disappears, her mother finds solace at the bottom of a bottle, and the only way to keep afloat is to turn a blind eye to the smugglers who send signals from the clifftops. But Emily knows that the smugglers killed her father to ensure his silence, and she will not let his murder go unpunished.... 

England, 1943: Deciding to throw herself into war work, Nancy Callaghan joins the Special Operations Executive in Baker Street. There, she begins solving ‘indecipherables’ – scrambled messages from agents in the field. Then Nancy meets Tom Lockwood, a quiet genius when it comes to coding. Together they come up with the idea of printing codes on silk, so agents can hide them in their clothing to avoid detection by the enemy. Nancy and Tom grow close, and soon she is hopelessly in love. But there is a traitor in Baker Street, and suspicions turn towards Tom.

The occupation has taken much from the Cotillard sisters, and as the Germans increase their forces in the seaside town of Boulogne-sur-Mer, Gabriella, Martine and Simone can’t escape the feeling that the walls are closing in. Yet, just as they should be trying to stay under the radar, Martine’s discovery of a British messenger pigeon leads them down a new and dangerous path. 

Rhoda Middleton suspects her husband Peter is having an affair. But when Rhoda tracks the mysterious woman down, she finds she is not his lover after all, but the wife of his wartime best friend, Archie Foster. There is only one problem - Rhoda has never even heard of Archie Foster.