Michal (Maciej Zakoscielny), a young and carefree architect with everithing he wants, wakes up one morning in his house with a little girl (Julia Wróblewska) called Michalina , who claims to be his child. Now he will have to take care for her during a week while he tries to discover who is her mother. Little by little, Michalina conquers Michal's heart at the same time the weeks comes to an end.