question: What screenwriter married M1 's spouse
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.writer .
  ?x0 ns:people.person.spouse_s/ns:people.marriage.spouse|ns:fictional_universe.fictional_character.married_to/ns:fictional_universe.marriage_of_fictional_characters.spouses ?x1 .
  ?x1 ns:people.person.spouse_s/ns:people.marriage.spouse|ns:fictional_universe.fictional_character.married_to/ns:fictional_universe.marriage_of_fictional_characters.spouses M1 .
  FILTER ( ?x0 != ?x1 ) .
  FILTER ( ?x1 != M1 )
  }