What Happens in the Highlands by Anna Bradley

Three unusually gifted sisters in Georgian Scotland must protect their family fortress from those who would steal its rumored treasures—and their hearts—in this sweeping, adventure-filled, new historical romance series for readers of India Holton, Lex Crocher, Manda Collins, and Evie Dunmore.

In the months since their father, Rory, died, the MacLeod sisters have had to contend with bands of smugglers convinced he left a treasure buried within the walls of their home at Castle Cairncross. Only the most mystifying occurrences have foiled the thieves—stirring whispers that the sisters are sorceresses. Yet, they have no treasure, nor are they witches. However, each inexplicably possesses a unique ability. The eldest, Catriona, is a brilliant healer and alchemist—a skill she is about to put to unforeseen use . . .
Hamish Muir, the charismatic Marquess of Ballantyne and son of Rory’s business partner, has come to claim his share of the treasure. When he spies fiery-haired Cat in the village, he follows her. But the tables turn, and Hamish finds himself at Castle Cairncross—emerging from a daze . . .

Persuaded the castle harbors no treasure, Hamish remains certain Rory hid it somewhere. Cat offers a proposal: She will help Hamish decipher her father’s notes if he takes her on the treasure hunt with him—and her sisters are not left alone. Reluctantly, Hamish summons two Lairds to the castle. But as he and Cat set off to navigate a maze of maps and danger, a mutual respect—and attraction—ignites between them. Perhaps the real treasure isn’t gold after all . . .