A protective Dr Gibson sends 17-year-old Molly to the Hamley's, where she falls for eldest son Osborne, and then trouble erupts. Molly also has to come to terms with her father's plans to remarry, to widow Hyacinth Kirkpatrick, who has a daughter around Molly's age.

Osborne's banishment from Hamley Hall triggers Mrs Hamley's terminal decline. Before leaving for Africa, Roger proposes to Cynthia and is accepted. Molly faces problems with her stepmother and her views.

Cynthia's secret engagement to Mr Preston comes to light. When she tries to break it off, Preston is reluctant to let her go or return her letters. After a visit to London, Cynthia also breaks off her engagement to Roger, who is on an expedition in Africa. Osborne's health decreases quite severely. Fearing his father's reproach, he still cannot tell him of his marriage to a French woman or his having a child.

Roger returns from Africa after Osborne's death to find his sister-in-law and his nephew living at their home as well. Cynthia has accepted the proposal of lawyer Mr Henderson, while Roger seems to have his heart set on Molly.