Indigo Moon. Dark Lords and Dangerous Ladies, #5

Another classic Regency novel from NYT bestselling author Patricia Rice: London, 1812: In a world teetering on the edge of change, survival may depend on who they dare to trust. In a year when England is at war with Napoleon, the prince has been named regent, and Parliament braces for upheaval, scandal is the least of Lady Aubree's concerns. As the only daughter of a powerful duke, Lady Aubree is accustomed to privilege and influence-until the day her father denies her the man she wishes to marry.
Defying his decree, she allies herself with the enigmatic and notorious Earl of Heathmont, a man whispered to have murdered his first wife. Heathmont, driven by urgent military imperatives, has his own reasons for drawing the duke's attention. Aubree's bold proposal offers him a chance to expose a dangerous adversary, even as it threatens both their reputations. What begins as a calculated alliance soon entangles them in a web of political maneuvering, hidden enemies, and the volatile currents of a nation at war. As betrayal closes in from unexpected quarters, Aubree and Heathmont must confront secrets capable of destroying far more than their fragile partnership.
In a world teetering on the edge of change, survival may depend on who they dare to trust. Dark Lords/Dangerous Ladies in order:Book 1: Love Forever AfterBook 2: Silver EnchantressBook 3: Devil's LadyBook 4: Dash of EnchantmentBook 5: Indigo Moon