Lady Violet Hughes is keeping secrets. First, she founded a clandestine sanctuary for England's most brilliant female scientists. Second, she is using her genius on a confidential mission for the Crown. But the biggest secret of all? Her feelings for protection officer Arthur Kneland.

Solitary and reserved, Arthur learned the hard way to put duty first. But the more time he spends in the company of Violet and the eccentric club members, the more his best intentions go up in flames. Literally.

When a shadowy threat infiltrates Violet's laboratories, endangering her life and her work, scientist and bodyguard will find all their theories put to the test—and learn that the most important discoveries are those of the heart.