"It's an enigma, wrapped in a blanket of secrecy, bound with a web of deceit."

In the summer of 1939, Jessie Fordham graduates from Cambridge University with a mind buzzing with academic achievements but a heart burdened by family strife. Jessie is travelling to her parents' summer house, le lac de minuit, the midnight lake, nestled in the tranquil French Ardennes. Yet, Jessie dreads the impending months, haunted by memories of a fractured childhood spent evading confrontations with her father, Albert, and stepmother, Armel. Suspicions of their clandestine affair during her mother's illness linger, casting a shadow over family bonds.

As tensions simmer beneath the idyllic facade of midnight lake, the Fordham family reunites against the backdrop of looming war. With the spectre of conflict hanging heavy in the air, Jessie's world is upended when Germany's invasion of France in May 1940 thrusts her father, Albert, into the heart of diplomatic turmoil as Britain's Military Attaché to France.

Summoned to the British Embassy in Paris, Albert entrusts Jessie with a perilous mission: safeguarding a crucial secret and delivering it to British intelligence in London. Charged with the safety of her siblings and household staff, Jessie finds herself entangled in a desperate gambit to navigate the treacherous landscape of wartime Europe.

With Dunkirk as their beacon of hope amidst the chaos, Jessie must summon every ounce of wit and courage to protect her charges and safeguard her father's clandestine mission. From the dense foliage of the Ardennes Forest to the battered streets of Dunkirk, Jessie's journey is a testament to resilience in the face of adversity, where loyalty, sacrifice, and the bonds of family are tested to the limit, amidst the tumult of war.