It was the desire to portray ghostly elf creatures hovering on stage, which in the 19th century led choreographers to carry the theatrical dancing to the extremes and to elevate the ballerina on the toes of her feet. In mostly uncanny scenes supernatural creatures were up to mischief.
In Giselle it is the dance-addicted Vilis around whom the libretto is entwined. Vilis are fairy creatures who died as brides before their marriage because their love was betrayed. The sensitive Giselle is supposed to become one of the same, because she loves not only dancing, but also Albrecht, who is wooing her, even though he is already engaged to somebody else. Finally realizing the truth, Giselle is losing her mind and dies. Giselle is included into the bevy of the Vilis and, like her companions, is now condemned to seducing men into dancing at night until they die. Myrtha, the Queen of the Vilis, is watching over it. Albrecht also comes to the forest to visit Giselle's grave.
The choreography was adjusted to fit the current hygiene measures.