Lady Rose Summer couldn't be more delighted to assist Society's most beautiful new debutante, Miss Dolly Tremaine, in negotiating her very first Season. Now engaged to Captain Harry Cathcart in order to avoid being shipped off to India, Rose is desperate to do something more useful than attend endless balls and parties. The country-bred Dolly is totally at sea--and needs all the help Rose can give, but when Rose rushes to prevent Dolly from making a disastrous mistake, she discovers her stabbed to death and floating in a boat on the Serpentine River. It isn't long before Rose barely survives an attempt on her own life.