On the morning of his marriage to Effie, James, a Scottish farmer, is visited by a mesmerizing forest spirit - the Sylph. She flutters in the air around James, who is sleeping by the fireplace, and wakes him up with a kiss. James is enchanted by the Sylph and tries to catch her, but she disappears. When the guests arrive, so does the Sylph, but she is visible only to James. Madge, the witch, prophesizes that Effie is to have a different husband – Gurn; James chases her away. She leaves, harbouring resentment towards him. During the wedding the Sylph appears again and steals the wedding ring. Unable to resist her charms, James rushes after her, leaving the grief-stricken Effie behind.
The witch is bent over a boiling cauldron: she has a long transparent scarf in her hands. The kingdom of the Sylphs in the magic forest. James is following the elusive Sylph, but he is unable to grasp her in his hands. She appears before him and gives him water from the spring and some berries. James tries to catch her, but the Sylph is beyond his reach. The witch offers James a magic scarf that can help him catch the Sylph. It works. When James throws the scarf over the Sylph’s shoulders, she loses her wings and her ability to fly, but with it – her ability to live. Her friends carry the dead Sylph into the clouds. James is in despair.
A wedding party is seen in the distance – Effie is getting married to Gurn.