An engagement shattered, a gallery career ruined by embezzlement, and life in London reduced to ruins, leaving Emma fleeing with nothing but a letter from her grandmother hinting at a treasure concealed in the enchanting streets of Montmartre. It is only when she boards the last train to Paris that her world begins to calm; a storm mirrors the chaos within her life.

Emma's encounter with Liam, a travel writer with a web of secrets, is the start of a romance that will keep you hooked. Their simmering suspicion turns into irresistible chemistry, but both are hiding dangerous truths. Emma's precise sketches of the train's layout fuel Liam's suspicion, and his hushed phone conversations about mysterious "packages" chill her to the bone. Reality check: neither is who they claim to be.

The tempest is just the onset. Emma's history as an insurance investigator specialising in art fraud reveals her relentless pursuit of uncovering a grand forgery conspiracy—captured wartime art meticulously disguised as legitimate artworks and commercially traded. Liam's facade as a travel writer veils his covert operations with Interpol within the same criminal network. Their delayed train, suspicious fellow travellers, and an overly helpful conductor all contribute to the elaborate trap.

Exploring the Montmartre area, Emma learns more of her grandmother's apartment—a supposed safe house turned into a Resistance member's estate transformed into a stronghold brimming with secret passageways and concealed rooms. But the ultimate betrayal is yet to come. Her grandmother Margot, whom she assumed dead, turns out to be very much alive and the diabolical puppet master orchestrating it all.

A brilliant hybrid of intricately woven historical mysteries, revealing secrets, tension-filled romances, and cloak-and-dagger art crime that will leave you guessing until the very end.