Her Grace's Passion (Bad Husbands #3)
Marion Chesney, M.C. Beaton

Matilda, Duchess of Hadshire, was a virtual prisoner of a cruel husband who romanced his mistress under her nose. Her only joy was dreaming of the handsome Earl of Torridon--for he, too, was trapped in a horrid marriage and longed for love and happiness.
Though she secretly wished for his death, Matilda never imagined the guilt that would plague her when the illustrious duke was befittingly murdered by his own lightskirt! And when she turned to Torridon for comfort, she discovered a few surprises in store for both of them....
This book is connected to The Scandalous Lady Wright & His Lordship's Pleasure .