Fortune's Gamble. Fortunes of Fate, #3

Christian Barnes never meant to steal his half-brother's identity, but when Major Andrew Bradford, Viscount Trowbridge, falls at Waterloo, Christian grabs his chance at the life he should have had as his father's oldest son. He and Andrew could have been twins, and he knows he'll get better care for his own wounds as a major than a private. The masquerade is so successful, he continues it once he returns to England.
However, he hadn't prepared for Rebecca Davenport, the fiancee Andrew had left behind. Lady Rebecca Davenport imedialtely realizes that Andrew has returned to her a different man. She just isn't quite sure if it's the years he's spent at war that have changed him. But as her suspicions grow, she realizes that the changes are welcome. This man is much better than the one she used to know. But can she hold her tongue and actually marry this imposter?