A movie sound recordist accidentally records the evidence that proves that a car accident was actually murder and consequently finds himself in danger.
When an assassin shoots a blackmailer and his beautiful female companion dead, he's paid off in marked bills by his treasonous employer who's working for foreign spies.
In 1960s Germany, criminal mastermind Dr Mabuse uses hypnotised victims and the surveillance equipment of a Nazi-era bugged hotel to steal nuclear technology from a visiting American industrialist.
