The Major's Guarded Heart (Harlequin Historical)

is book #368 in the Harlequin Historical line that is sold exclusively online from Harlequin rather in stores.
==Book Description==
HAS THE MAJOR FINALLY MET HIS MATCH? 
From the moment ladies' companion Elizabeth Ingram sees the imposing major Sir Justin Delacourt, her head is full of romantic ideas—ideas that end with Lizzie being caught trespassing on his estate, mistaken for a poacher! 
Despite his disdain for womanly wiles, Justin can't get the lively Lizzie out of his mind. And when she joins him in his quest to investigate a friend's mysterious disappearance he realizes that a woman of Lizzie's courage and determination might also be capable of stealing his heart…
(Description from harlequin.com)