Autumn in Scotland by Karen Ranney.
An English bride is deserted by her husband after one week. She decides to travel to her husband’s castle in Scotland, only to discover that it is empty and nearly abandoned. She stays there to avoid returning to London in disgrace.
Eventually, her husband comes back but he has changed quite a bit since she last saw him. It’s very Return of Martin Guerre.
Very entertaining but not exactly believable. I was more interesting in the subplot with the Asian friend who tags along with the husband. I really wish that the story had been about him instead.