Jacobus Spaargaren wants a better life for his daughter Marleen than he had himself. But when his wife unexpectedly becomes pregnant, Jacobus calculates the extra spending will put a halt to Marleen's planned study.

On Marleen's first day working as a maid for the Oudemans family, her father is fined for making a monetary error at the bank.

Marleen's colleague Sien introduces her to her son Herman, who teaches Marleen to ride a bicycle. But when Jaap Oudemans tries to grope Marleen, she ends up losing her job.

Marleen gets a new job working for newspaper journalist Jan Griffioen and soon develops a crush on him. But when the Great War erupts, Griffioen has to report at the front.

During the Great War Marleen is courted by a Belgian soldier named Jef Verpoorte who asks her to become a Catholic. Afterwards she goes to work as a maid for Professor Buwalda.

Marleen meets the depressed but kindhearted Jan Engelmoer. When she returns home, she is dismayed to find Mrs. Buwalda dead in her bed.

Mrs. Scalonje moves into the Buwalda household after the death of Mrs. Buwalda. Marleen asks Jan Engelmoer to fix an antique chest owned by Professor Buwalda.

Despite objections from her parents and her employer, Margreet wants to marry Jan Engelmoer. She quits her job as Buwalda's maid and moves in with Jan.

Professor Buwalda visits 'Het Klein Verschil' to apologize to Marleen. As their little antique shop grows, Marleen collects all sorts of rarities in and around Amsterdam.

After the death of Jacobus Spaargaren, Marleen asks her mother to come stay with her and Jan offers 15 year old Eppo a job as his assistant.

Marleen arranges a place to stay in the country for depressed Alie Donkelaar and takes the care of Alie's three children upon herself.

When the loudmouth and rude artist Jos Boswinkel enters Het Klein Verschil, he and Marleen start arguing almost immediately. But she still asks him to take a look at the work of her brother Eppo.

Mrs Scalonje offers Marleen the chance to learn how to drive a car. Dr. Bresser informs Marleen that her husband Jan can never conceive a child. But Marleen, who desperately wants a child, refuses to tell Jan the truth.

Desperate to get pregnant, Marleen asks Jos Boswinkel to impregnate her, then forbids him to speak of it ever again.