Tom Lawrence, the debonair sleuth known as "The Falcon," becomes entangled in an investigation when Jane Harris, a student at the Blue Cliff Seminary for Girls, asks for his help, claiming that recently deceased Professor Jamison did not die of natural causes, as stated on his death certificate, but was murdered. After Jane informs Tom that her roommate, Marguerita Serena, had foretold Jamison's death, she steals Tom's car, forcing him to follow her to Blue Cliff. At the seminary, Tom meets the school's furtive psychology teacher, Anatole Graelich, and the dean, Miss Keyes. Tom tells them that he is an insurance investigator looking into the death of Professor Jamison and inquires about Marguerita's prediction. As Tom questions Miss Keyes, a phone call comes from the dead professor's room, and they go to investigate. At the professor's cottage, Tom and Miss Keyes find Mary Phoebus, the school's music teacher, who maintains that she has come to look for the professor's poems. After Tom confiscates the verses, he tracks Jane and his car to the school's rehearsal hall, where he meets drama teacher Vicky Gaines. During the rehearsal, Tom watches as Marguerita refuses to use the prop foil, claiming that it will cause another death. Backstage, Tom overhears Vicky and Graelich whispering, and follows Vicky to town, where she visits undertaker Eustace Herley. When Tom finds sleeping pills in Herley's lab, the undertaker admits the Jamison committed suicide by taking an overdose. Tom then offers Vicky a ride back to school, and during their drive, he shows her a poem that Jamison dedicated to "V. G.," causing her to confess to feeling guilty about his suicide. Soon after, police inspectors Timothy Donovan and Bates arrive at Blue Cliff to investigate Jamison's death, and Tom declares that he knows who the killer is. That night, the school revue is interrupted by the screams of Marguerita, who has just found the body of Miss Keyes with the foil next to it. Tom follows Marguerita to Graelich's cottage, where she confides that she fears she has inherited her father's insanity. After Marguerita leaves the room, Tom finds a picture of Vicky taken on a European cruise, and when Graelich appears, Tom suggests that the psychologist's jealousy of Jamison may have been the motive for his murder. Graelich denies this and informs Tom that he has married an American so that he can legally enter the country, but that his marriage has remained secret because Miss Keyes would not allow married teachers on the faculty. Soon after, a shot rings out, and Tom traces it to the girls' dormitory, where he meets Vicky in the hallway. In her room, where Tom sees the same cruise picture, and Vicky admits that she met Graelich in Europe and fell in love. Drawn by the gunshots, the group reconvenes in Dean Keyes's office, where Donovan begins to interrogate Marguerita. Becoming hysterical, the girl runs away, and fearing that she may throw herself from the cliff, they pursue her. Tom teams up with Vicky, who admits that she broke her engagement to Graelich, thus causing Tom to deduce that the psychology professor then wed Mary who, out of insane jealousy killed Jamison and Miss Keyes to frame the lovers for murder. Mary is the first to reach the cliffs, and when Marguerita tells her that she saw her standing over the dead body of Miss Keyes, Mary tries to force her to jump. At that moment, Tom calls to Mary, and as she turns, she loses her footing and falls from the ledge. With the murders solved, Jane's mother, a famous performer, arrives at the school with another actress, who enlists Tom in solving a murder at the theater.
