A Lady Betrayed — Kate Silver

REVENGE MIGHT BE SWEET...
Courtney Ruthgard may have been spoiled by her wealthy father, but she never considered herself foolish. Not until she gave her heart--and much more--to a dashing Musketeer in the service of the king. Breaking her heart would have been one thing, but Pierre de Tournay stole papers incriminating Courtney's father in an illegal scheme. Suddenly penniless and alone, Courtney's only desire was to take revenge on the man who had betrayed her...and infiltrating the King's Guard was the perfect method.

...BUT DESIRE WAS UNDENIABLE
For Pierre, the arrival of Courtney's young male cousin in the Guard was a godsend. Finally he had a sympathetic friend who would listen to his guilty outpourings about what the king had forced him to do, and the painful regret he felt for hurting Courtney. But when a dangerous rebellion threw them into the fray together, he learned that his new comrade in arms was none other than the woman he loved--and that his greatest battle would be proving to her that his heart has always been true.