Ellery Queen, the scholarly amateur detective created in 1928 by cousins Frederic Dannay and Manfred Lee (who also used "Ellery Queen" as a joint pseudonym), was introduced to the screen in the low-budget mystery The Spanish Cape Mystery. Donald Cook plays Ellery Queen in a low-key, poker-faced fashion, which may not be terribly exciting but is actually closer to the original concept than most of the movie Queens. It all begins when Ellery and his friend Judge Macklin (Berton Churchill), vacationing at a California seaside resort, enter a lavish beach house and find pretty Stella Godfrey (Helen Twelvetrees) tied to a chair. More infuriated than frightened, Stella tells Ellery what the audience has already seen: while spending time with one of her relatives the previous evening, Stella was waylaid by a mysterious gunman (Rychard Cramer), who then knocked out her relative and carried him off into the night. Apparently Stella's relative has been murdered, one of several killings which occur during the film's brief running time. The mystery and motive are solved when Stella permits herself to act as bait for the killer, but the generous Ellery allows local sheriff Moley (Harry Stubbs) to take the credit. Originally released at 65 minutes, The Spanish Cape Mystery was edited to 54 minutes for TV showings.