To Hold a Lady’s Secret by Christi Caldwell

Return to the breathtaking world of the HEART OF A DUKE…the USA Today bestselling series that is sure to leave you sighing and longing for more!

Lady Gillian Farendale is in trouble. Her titled father has dragged her through one London Season after another, until the sheer monotony of the marriage mart and the last vestige of Gillian’s once-independent spirit conspire to lead her into a single night of folly. When her adventure goes so very wrong, she has only one old friend to whom she can turn for help.
Colin Lockhart’s youthful friendship with Lady Gillian cost him everything, and a duke’s by-blow had little enough to start with. He’s survived years on London’s roughest streets to become a highly successful Bow Street Runner, and his dream of his own inquiry agency is almost within his grasp.
Then Gillian begs him to once again risk angering her powerful father. The ruthless logic of the street tells Colin that he dare not help Gillian, while his tender heart tempts him to once again risk everything for the only woman he’ll ever love.