| Actor | Elliott Gould (as Sean Rogers), Trevor Howard (as Colonel Azarin), Joseph Bova (as Dr. Martino / Lucas Martino), Edward Grover (as Finchley), John Lehne (as Haller), James Noble (as General Deptford), Lyndon Brook (as Dr Barrister), Michael Lombard (as Dr Besser) |
| Based on the Novel by | Algis Budrys |
| Director | Jack Gold |
| Produced By | Barry Levinson |
| Written By | John Gould |
| Links | https://en.wikipedia.org/wiki/Who%3F_(film) · https://www.imdb.com/title/tt0072405/?ref_=nm_flmg_act_174 |