Genevieve Sturbridge has left the dangers of London for a quiet life in the countryside with her husband and young son. But when she is invited to a dinner party at Sir Horace Walpole’s magnificent Gothic estate, she is drawn into a terrifying web of deception, espionage and murder.

At the mysterious dinner party Genevieve makes a shocking discovery — a secret pigment of the deepest, purest blue is being produced once more. The formula is so rare, it’s the obsession of chemists, royalty, and spies. 

Some will kill to possess it. Others will kill to keep it buried. 

Only Genevieve can recognise the formula and stop it falling into the wrong hands. But when a ghost from her past resurfaces, Genevieve must determine who she can trust. Years ago, this secret nearly cost her and her husband their lives. Now, someone is willing to kill for it once more. 

Genevieve must discover the truth before time runs out, because this time the price of failure will cost more than just her own life. 

This thrilling historical mystery, with its captivating plot of secrets, murder and espionage is perfect for fans of Irina Shapiro, Anna Lee Huber, Emily L. Finch, Kate Morton, Andrew Taylor and C.J. Sansom. 

Praise for The Versailles Formula 

‘In Genevieve Planché, Bilyeau has created a wonderfully wilful woman: as smart as she is sensitive, as brave as she is bold. Compelling to read . . . This is a series going from strength to strength.’ Kate Braithwaite 

‘The Versailles Formula takes readers on a fascinating journey to eighteenth-century England and France, where vicious aristocrats play a deadly game of forgery and espionage . . . Nancy Bilyeau treats us to another tale full of intrigue and delightful historical details.’ Mark Alpert, internationally bestselling author of The Doomsday Show 

‘Sumptuous and deeply engaging, Nancy Bilyeau's Versailles Formula is a gorgeously written adventure . . . brimming with mystery, beauty, romance, and history's most fascinating luminaries.’ Emilya Naymark, author of 'Behind the Lie'

‘A plucky heroine, intriguing mystery, and rich, well-researched historical background. Nancy Bilyeau has found the winning formula!’ Eva Stachniak, author of The School of Mirrors