Marie is confronted with the fact that her fire brigade colleague Gerhard's wife is suffering from cancer. She insists that this remains a mystery - even to her own children.
Marie appeals to Camilla's conscience, but to no avail. When Daniel, who Marie hired as a babysitter for Gerhard's daughters, accidentally discovers the secret, he lets the two girls in on the secret. To the great annoyance of Gerhard, who is already completely overwhelmed.
Marie and Stefan just moved in together and - despite Marie's unexpected encounter with her ex-boyfriend Philipp – are newly in love. Marie's father Ernst is inconsolable now that she has moved out. And when his wife Irene wants to build a guest room in the house, his summer seems to have ended. The only thing that saves him is the prospect of coaching Marie for her fire brigade exam.