It feels like if I describe more than about 10 pages of this book I am getting into spoilers, because there were a few unpredictable things right near the beginning, so be warned....
Sandy, a young American heiress, is about to take a trip to England with her aunt and cousin. She toys with the idea of somehow running into her childhood hero, a soldier and generally famous man named Sir Miles Culver, but knows it won't happen. Before she leaves America, a new, slightly mischievous, acquaintance gives her a letter of introduction to a friend in England. Sandy seeks out this lady once she arrives, and finds out that she is one of the closest, oldest friends of......you guessed it, Sir Miles Culver. He himself makes an appearance that same afternoon, with.....his brand new fiancee. Sandy is a little shaken by this unpredictable first meeting, and gets out of there as fast as she can.
Fast-forward some days, and there is an awful automobile accident. The fiancee is killed, and Sir Miles' younger brother is crippled. Sir Miles hasn't the funds to provide the necessary medical care and comfort his brother needs.
The new friend, Lady Melton, knows that Sandy likes Sir Miles. She cooks up a plot, whereby Sir Miles and Sandy will get married and Sandy's money will be available for the care of the younger brother. There's just one catch: Sir Miles might agree to this for the sake of his beloved brother, but only if he thinks that it is a straightforward business arrangement and that Sandy is a calculating husband-hunter who wants a title, social class, and nothing else. So she can't let him see that she cares, or else, in fairness to her, he would call it off.
Decent story, though the melodramatic resolution at the end felt like it didn't quite belong to the same story.