A Winter's Knight by Donna Hatch

Clarissa's coach breaks down in front of the most forbidding estate in the county, Wyckburg Castle, a place where young brides have been murdered for generations by their husbands. Clarissa is horrified yet curious all in the same breath. When she meets widower Earl of Wyckburg, she must decide if she should flee or uncover the greatest secret in the county about her handsome rescuer.