Highland Thunder (Isle of Mull Series) by Lily Baldwin

The sequel to To Bewitch a Highlander

A storm is coming...

Brenna's famed composure is unshakable even when faced with tragic loss. But when she finds herself at the mercy of the one man she despises, her nurtured restraint is shattered.

He does not look at her or speak to her, and most importantly, he does not touch her. These are the rules Duncan set for himself long ago to ensure his affection for his best friend's wife remained undetected. But under the weight of a land besieged by war, the walls he erected to shield his heart crumble.

If he can earn her trust, the one woman he has always loved may at last be his. But first he must save what he cherishes most from a nightmare of dark secrets.