Christian Kempenich, a pedantic law firm manager, attends a christening in Cologne, leading to a boozy night. He wakes up in a stranger’s bed and is accused of stealing bed linen from the hotel. Meanwhile, his wife Hedwig had her own fling and wants to keep it secret. When she learns of Christian’s predicament, she reveals her affair during a heated discussion. Realising their marriage is at risk, they decide to work on their relationship.

Lothar von Pütz and Roswitha von Krakow fall in love and only then discover that their fathers are bitter enemies. When Lothar's father dies, a close friend of his father's, Baron Maximilian von Hanckel, takes the boy under his wing and tries to make peace between the families. He visits Roswitha's father, who begins to hope that he can marry his daughter to the older, but wealthy, baron, who is still a bachelor. When an argument breaks out between Lothar and Roswitha, she agrees to marry Maximilian. It is only at the pre-wedding party that Roswitha and Lothar have a real conversation. Maximilian overhears everything, releases Roswitha from her vows, and brings the two young people together.

Based on an 1884 novel by Julius Stinde, it is a family chronicle set in late nineteenth century Berlin.

As the title "The Queen's Heart" suggests, this early German black and white version of Mary Queen of Scott's eventful reign and death focuses on her emotional perception rather lyrically, with some songs, mainly by her.