[4] At the Arts for the Living Center in New York, Candice Norman (Olga Karlatos) oversees the latest dance routine choreographed by Margie (Geretta Marie Fields).
That evening after the dance class is over, one of the dancers, Susan, is murdered in the locker room by an unseen person who chloroforms then stabs her in the heart with a long hairpin needle.
With Candice nowhere to be found, suspicion begins to focus not only on her but on the victim's boyfriend Willy Stark (Christian Borromeo), as well as Dick Gibson.
The next day, the routine at the campus continues as normal, causing Dick a great deal of upset, since nobody seems to care about Susan's death.
Panicked, she runs to the front door, where she is attacked and killed by the unseen assailant who thrusts a hairpin needle into her heart.
Candice begins having nightmares of being attacked by a handsome young man (Ray Lovelock) wielding a long, ornamental needle identical to the one used in the killings.
Unable to shake the feeling that they are in some way predetermined to meet, Candice tracks down the man in the poster to the seedy Fulton Hotel, and bribes the desk clerk for the key to "Mr. Robinson's" room.
George goes to the academy to return Candice's purse where another dancer, Gloria, recognizes him from a modeling show they appeared in years earlier.
Over lunch at a local Chinese restaurant, the relationship between Candice and George becomes closer when she confides in him about an incident years earlier, when a man on a motorcycle ran her over in a hit-and-run putting an end to her dancing career and forcing her to teach.
Back at Candice's apartment, she gets a phone call from Phil (Lucio Fulci), a local talent agent, who has made a background check for her on George and informs her that he once had an affair with a young girl who later died.
In addition, Candice told them details about the lion's head hairpin needle used in the killings, information that, since it had never been made public, only the killer could know.
[5] In an interview, director Lucio Fulci stated that the movie was part of a "Music Trilogy" that would include two more gialli: Killer Samba and Thrilling Blues.