Audrie Brendon, a young woman teaching in a French school, agrees to impersonate her wealthy pupil and friend, Ellaline Lethbridge. Ellaline is desperately in love with a French lieutenant and wishes to avoid her guardian, Sir Lionel Pendragon, who has returned from Bengal to manage her affairs. Audrie meets Sir Lionel at the station, expecting a stern and unfeeling dragon, but instead finds a cultivated, honorable man. Sir Lionel, his sister Mrs.
Norton, and Audrie embark on a luxurious motor tour through southern England, visiting historical sites, Roman villas, and the New Forest. Along the way, Audrie finds herself deeply drawn to Sir Lionel, despite the deception she is maintaining. Complications arise when Richard Burden, a young man who has uncovered the plot, joins the tour with his aunt, Mrs. Senter, who has her own designs on Sir Lionel. As claims, discoveries, and romantic tensions mount, Audrie struggles between her loyalty to Ellaline and her growing feelings for Sir Lionel, knowing her true identity must eventually be revealed.
