Two competing teams of scientists search the African jungles for a secret formula.
Richard Alexander | Noah Beery Jr. | Eddie Parker | Stanley Andrews | Bryant Washburn | Don Brodie | Dickie Jones | J.P. McGowan | Eddie Kane | Walter Miller | Harry Woods | Dorothy Short | Russ Powell | John Davidson | Hal Taliaferro | Harry Worth | Eric Mayne | Charles Murphy | Gwendolyn Logan | King Baggot | Grace Cunard | Al Ferguson | J. Frank Glendon | Viva Tattersall | Buddy Roosevelt | William Desmond | Fred MacKaye | H. Burroughs