Although the title (which translates as "Murders in Chicago") promises a gangster story, this is more of a murder mystery that kicks off with the seemingly accidental death of a construction worker, followed shortly after by that of a noted publisher (an uneasy-looking Eduardo Fajardo). What follows is a very confusing story in which the police, a police coroner (José Campos) and a vagrant (Fernando Sánchez Polack) who witnessed Fajardo's death embark on separate inquests on what actually happened. Meanwhile, June (María Luisa Rubio), who works as a secretary for the publishing company, is under pressure by a blackmailer (Antonio Jiménez Escribano) who has pictures of her in the sack with the deceased publisher.
| Actor | Role |
|---|---|
 José CamposNot listed | Not listed |
| JJosé TruchadoNot listed | Not listed |
 Fernando Sánchez Polack(as Fernando S. Polak) | (as Fernando S. Polak) |
| MMaría Luisa RubioJune | June |
 Isana MedelGladys | Gladys |
| MMarian BruNot listed | Not listed |
| EErnesto ArronizNot listed | Not listed |
| BBernardette BernierNot listed | Not listed |
| JJuan Antonio SolerNot listed | Not listed |
| AAntonio EscalesNot listed | Not listed |
| JJulio CifuentesNot listed | Not listed |
 Guillermo MéndezNot listed | Not listed |
| MManuel Díaz Velasco(as Manuel Díaz) | (as Manuel Díaz) |
| FFrancisco JoséNot listed | Not listed |
 Antonio Jiménez Escribano(as A. Giménez Escribano) | (as A. Giménez Escribano) |
 Eduardo FajardoArthur | Arthur |