Who was M1 's British writer 's employer 's founder 's sibling
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings ?x1 .
?x1 ns:organization.organization_founder.organizations_founded ?x2 .
?x2 ns:business.employer.employees/ns:business.employment_tenure.person ?x3 .
?x3 ns:film.writer.film M1 .
?x3 ns:people.person.nationality ns:m.07ssc .
FILTER ( ?x0 != ?x1 )
}