When Wheatley is meeting with Assistant US Attorney Baldi in an attempt to get a plea bargain he names off one of his associates, Masanori Watanabe. Upon hearing his name AUSA Baldi whispers "Yamaguchi-gumi" to his assistant. The Yamaguchi-gumi are the largest member of the Japanese Yakuza, which is Japan's largest and most powerful crime syndicate. The Yamaguchi are one of the largest criminal organizations in the world, with a reported 8,200 active members. They are also ranked among the world's wealthiest gangsters, making billions of dollars a year from extortion, gambling, prostitution, sex trafficking (especially trafficking underage Japanese girls), arms trafficking, the import and export of drugs, especially the export of raw opium to be made into heroin. They also have experience with stock market manipulation and are one of the world's largest producers of internet child pornography.
Novichok (Russian for "newcomer" or "novice") is a term for a group of binary nerve agents developed by the Soviet Union between 1971 and 1993. A binary nerve agent is one that is made by mixing two different precursor chemicals together, before mixing the precursor agents are inert and safe to handle and transport, they do not become dangerous until the two precursor components are mixed together. There were four objectives a nerve agent had to meet in order to be considered a "Novichok": it was to be undetectable by standard NATO chemical detection equipment from the 1970's and 1980's, it had to penetrate standard NATO chemical protective gear, it had to be safe to handle and transport, and finally it had to be made of chemicals that were not on the Chemical Weapons Convention list of controlled chemical precursors. While the Soviet Union does not exist anymore, and the Russian Federation claims to no longer make these agents, black market chemists have discovered how to make them and they are often sold to criminal organization for use in assassinations.