False Colours — Georgette Heyer

When the charming but irresponsible Lady Amabel, Countess of Denville is left a young widow the problem of her mounting debts becomes acute. So she is lucky to have such resourceful twin sons as Evelyn and Christopher Fancot to steer the family through a desperate intrigue to restore the Denvilles fortunes. The danger is that, at times, the family's pressing financial needs are almost overshadowed by the even greater demands of young hearts. But, just when disaster seems certain, their adorable Mama, quite unpredictably, saves the day.

The Honourable Christopher "Kit" Fancot, on leave from the diplomatic service in the summer of 1817, is startled to find his entrancing but incorrigibly extravagant mother on the brink of financial and social ruin - and more than alarmed to find that his twin, Evelyn, the new Earl of Denville, has disappeared without trace. Handsome and eligible as the titled elder of the renowned Fancot twins was, no one would forgive him if he failed to appear before his fiancee's family. For even though they did not love each other, he could hardly embarrass the charming Cressida Stavely at her own engagement party. And if the match were wrecked, it would dash the last hope of getting his lovely, improvident mother out of debt.

The incorrigible Lady Fancot persuades her younger son to impersonate his twin -- just for one night, she promises. Kit, appeared at the party just in time to double for the missing Earl. With his intelligence he succeeded in deceiving all present. Kit - is forced to continued the outrageous masquerade by the tangled affairs of his wayward family: his rigid uncle, Lord Brumby, the surprisingly wily Sir Bonamy Ripple, the formidable old Lady Stavely and Evelyn's betrothed, Cressy. But in the face of Evelyn's continues absence, Kit's ingenuity is stretched to the limit.... And with his superb manners he not only charmed Cressy's formidable grandmother, but made Cressy herself wonder if she could love her fiance after all... The masquerade sets off a tangled sequence of events that engage Kit's heart far more deeply than he'd ever anticipated with his brother's fiancee--who might know much more about what's going on than she cares to reveal...