Vivie Warren, a thoroughly modern young woman, has just graduated from the University of Cambridge with high honours in Mathematics (equal Third Wrangler). Her mother, Mrs Warren, who has been a distant figure during Vivie's childhood in boarding schools and college, arranges for her to meet her friend Mr Praed, a middle-aged, handsome architect, at the house where Vivie is staying. Mrs Warren arrives with her business partner, Sir George Crofts, who is attracted to Vivie despite their 25-year age difference. Vivie flirts with the youthful waster Frank Gardner. Frank's father, the Reverend Samuel Gardner, has a past history with Vivie's mother; indeed, he may be Vivie's out-of-wedlock father, making Vivie and Frank half-siblings.