Danger: Diabolik

In an unidentified European country, police inspector Ginko arranges to secretly transport $10 million from a bank using a diversion involving a wastepaper truck, while officers steal the money in a Rolls-Royce. This operation aims to prevent the master thief Diabolik from stealing the money, but the plan ultimately fails as Diabolik escapes with the cash and his lover Eva Kant. They retreat to their underground hideout to celebrate their success.

Diabolik and Eva attend a press conference where the Minister of the Interior reinstates the death penalty to deter criminals. They cause chaos by releasing intoxicating gas into the crowd, disrupting the event and drawing attention to their presence. This stunt showcases their defiance aimed at authorities.

The police realize they cannot locate Diabolik and focus their efforts on gangster Ralph Valmont, whose illegal activities include running a teen discotheque used as a front for drug trafficking. After raiding the club, they suspect him of aiding Diabolik, prompting the police to make a deal with Valmont to gather intelligence.

Diabolik decides to steal the famous Aksand emerald necklace from Château de Saint-Just for Eva's birthday. Valmont helps by creating an identikit of Eva based on information from a prostitute, which later leads to her recognition. Diabolik prepares for the daring heist by scaling the castle's walls while police await on the ground.

Diabolik successfully steals the emerald necklace by illegally entering the castle. During his escape, he and Eva deceive the police using a mirrored film and dummy decoys, but Eva is injured while setting up their trick. The theft highlights Diabolik's skills and daring approach to crime.

While visiting her private doctor, Eva is recognized from the identikit image circulated by Valmont and is kidnapped by unknown assailants. Her abduction prompts Diabolik to mount a rescue, indicating her importance to him and escalating the conflict with the authorities and other criminals.

Diabolik infiltrates Ralph Valmont's airplane, carrying the stolen money and necklace to trade for Eva. Despite being ejected from the plane, he manages to grab Valmont just before a bomb he set earlier explodes, demonstrating his resourcefulness and commitment to saving Eva.

After shooting Valmont with emeralds and seemingly committing suicide using a mysterious capsule, Diabolik appears dead, and his body is prepared for autopsy as the police and press gather. Eva, however, administers an antidote within twelve hours, enabling Diabolik to fake his death and evade capture.

Disguised as a nurse, Eva helps Diabolik retrieve the emeralds from Valmont’s ashes at the morgue where his body was cremated, allowing them to secretly keep the valuable stones. Their cleverness in recovering the loot underscores their cunning nature.

The police offer a million-dollar reward for Diabolik’s capture after realizing he is alive. In retaliation, Diabolik blows up the tax offices, causing widespread financial chaos and revealing the corruption within the government while establishing his defiant presence.

Diabolik melts twenty tons of stolen gold into smaller ingots to prevent theft and loads it onto a train. He and Eva sabotage the train with a burning truck and a bomb, causing it to derail and fall into water, enabling them to retrieve the gold and return to their hideout.

Police locate Diabolik's gold stash by tracking the steel casket containing the gold. During a confrontation, the smelting process goes awry, covering the entire cavern in molten gold. Diabolik’s heat-proof suit ends up covered in solidified gold, and the police seal the cavern, believing him dead.

As the police prepare to autopsy Diabolik, Eva secretly administers the antidote, bringing him back to life. Diabolik then visits the cremated remains of Valmont to recover the emeralds from his ashes and escapes once more, reaffirming his elusive persona.

The film concludes with Diabolik alive and spirited, winking at Eva as police close in on his last known location. The story highlights his ingenuity, daring heists, and ability to evade capture, cementing his reputation as an unmatched master thief.