Question: For what unfinished film was Sergei Eisenstein the editor?
Paraphrase: For what unfinished film was Sergei Eisenstein the editor?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P1040 wd:Q8003 . ?sbj wdt:P31 wd:Q18011171 } 
Answer: Ivan the Terrible. Part III