When Santana raised a concern about the quality of steel used in the Japanese Katana Blade, Bryan said it was "almost as good as the Vikings".
Clive Standen, the man who plays Bryan Mills, also starred as Rollo, Ragnar's brother, in Vikings (2013).
Persona Non Grata, is Latin for Non-Acceptable person. That is status assigned to an individual, whose diplomatic credentials are revoked by the host government.
The episode title Strelochnik is Russian for Switchman.
The Yakuza is the Japanese Mafia, or Organized Crime group.
Kilroy said that he was good friends with Edward Snowden, American who was a contractor with the National Security Agency, the government agency responsible for extracting intelligence from any communication medium. He eventually fled to Russia with sensitive information on the nation intelligence gathering apparatus, to raise concerns about breaches of privacy.