L'agent secret Lemmy Caution, envoyé à Alphaville pour détruire l'ordinateur Alpha 60, tombe amoureux de Natacha, la fille du professeur von Braun.

During the 1800s, Peru's government sends 2 envoys to negotiate peace with the rebellious Incas but a treasure-hunter bandit shoots the Inca ruler and his son, leaving the 2 envoys to take the blame for it.

Lady Lorraine Lister, a financer of expensive experiments, has discovered a way to obtain pure diamonds by the means of a radiation device. She hires five renowned scientists to participate in additional experiments regarding this new contrivance. However, it soon happens that the device is stolen, and the scientists mysteriously disappear! Agent Dick Smart is called in by the CIA to track down the scientists and recover the device. With the help of incredible gadgets and lots of bravado, he manages to locate the source of an underground operation in Rio De Janeiro: an operation headed by a mysterious man with a speaking device fastened to his throat.

Nick Carter rencontre le savant Fromentin, qui redoute l'intervention des gangs désireux de s'approprier ses inventions. Après avoir échappé à plusieurs attentats, Nick réalise que c'est l'entourage proche du savant qui complote contre lui...

Afin de récupérer une caisse de charges nucléaires, l'agent Nick Carter est envoyé à Amsterdam. Il a quatre jours pour retrouver les traces de ces mystérieuses roquettes avant qu'elles ne lâchent un gaz mortel sur l'Europe...

Part of Piero Bargellini's Lost Cinema.