In manufacturer Grøndahl’s mansion lives Amalie, a lovely young girl who was orphaned at an early age. Amalie’s only protector is Grøndahl, who is seeing to her education until she comes of age. But Grøndahl’s feelings for Amalie are more than just paternal. He spies on the young woman who never has a moment’s privacy. Amalie has a warm and good heart, but she suffers terribly under her foster father’s roof. Every day she dreams of escaping her tyrant and tormentor.
Using her feminine wiles, she devises a plan. Into a vase she drops a note with the words, "Whosoever releases me from my solitude shall have my heart. Amalie." Her entire future is now in the hands of the delivery boy, who transports the vase to the home of a young millionaire, Jack Morton. Soon, the vase breaks and he discovers the note. Outraged at the thought of a young woman suffering so, Morton vows to find Amalie.
When he finally finds himself face to face with her, he makes it his mission to set her free. But Grøndahl, ever suspicious, never lets them out of his sight. Late one night, Morton climbs to Amalie’s window. A thrilling chase ensues when Grøndahl discovers what is going on. He is hot on the heels of the escaping lovers when they chance upon a hot-air balloon about to ascend and clamber on board. But Grøndahl manages to grab hold of the end of a trailing rope and starts hoisting himself up. As the balloon rises to a high altitude, he loses his grip and plunges into the sea. Miraculously, he survives and boards another balloon. Carelessly, he lights a cigarette and the balloon explodes. At last, Jack Morton and young Amalie are free to pursue their happiness.