When the Second World War swept through Paris, Iris Penhallam paid the ultimate price to save the ones she loved. Fifty years later, her niece is determined to track down the truth of Iris's forgotten years.

Stella Penhallam needs a miracle. So, when her estranged great-aunt's journal lands on her desk, Stella knows that the missing pages hold the answers she seeks so she begins to re-trace the footsteps of the past.

In 1939, as war breaks out across Europe, Iris Penhallam vows to save her friends trapped in Mussolini's Italy. As a perfumer, she travels to Italy on the Orient Express under the guise of creating five exotic scents with her partner, Alessandro.

But when Iris's heart becomes intertwined with her mission, she pays the ultimate price to save the man she loves. A secret she will keep for a lifetime.

As Stella discovers what Iris lost, she's determined to uncover the truth of the perfumer's secret...