sentences:  Bo F. Munthe stated that Charles Aperia got the idea for the film after he saw a brief draft for a novel Munthe he was working on, entitled "Ninja-mördare i svart" ("Ninja Assassin in Black").Filming took place in Stockholm (Havregatan), Lidköpings city hospital and harbour (with the former acting as the Leningrad institute), as well as the Halden fortress in Norway (acting as the fake UN building used by the KGB).Although the film had a very modest release in its native Sweden, "The Ninja Mission" did well on the foreign market.