Molle Brendel's father gives her a new pet: a baby lamb. Bimbo Brendel meets a mysterious boy living in a tent. Günther Brendel's brother and sister-in-law are killed, and he adopts their orphaned children, Dany, Peggy, and Benny.
A mysterious new boy has been seen around the Suderhof. At the same time, Ben's pet lamb, Rosi, has gone missing. Without telling anyone, he runs away to find her. Meanwhile, Ben and Peggy attend their new school for the first time.
The mayor is hosting a horse race. Bimbo is eager to enter her pony, Klärchen. But her father tells her that her pony is too expensive and he will sell it. Now Bimbo has to win the horse race and the grand prize of 5000 marks.
Bimbo is at the bottom of her class in English. Her teacher, Dolly Malzahn, may hold her back a year. She seeks Peggy's help in improving her English grades, quickly.
