Danny Scipio arrives in London, from Italy, to liaise with Inspector Penrose having broken an LSD ring run by Thomas Calleia. He helps British police pick up the drug on it's arrival but the Mafia are waiting to even the score.
Danny Scipio is called in when North London villain Jackie Hunter is found dead, in a ritualistic killing, at funfair. Superintendent Savile suspects the Mafia, which leads Scipio into possible illegal immigrants used as casual labour.
Businessman Albert is murdered in barber's shop. A man named Anderson arrested in a hotel room. Albert's name was on Angelo James list as a member of the Mafia. Prosecuter Joe Drummond witness's start getting cold feet.
Martin, the son of businessman John Abram is kidnapped with a $50,000 ransom requested. After similar incident in Canada his wife says he should call in Angelo James but he fears if he pays the Mafia may still kill him.