Sophisticated crook talks ex-crook and now respectable business man into one last caper. This highly planned and well executed crime goes off without a hitch until rival bad guys want a piece of the action.
Whilst being transferred to a psychiatric hospital, a ruthless serial killer Gassot makes a break and goes on the run. He arrives in Marseilles, intending to escape abroad. Here, he falls for a young prostitute, Gerda.
With the financing of Jérôme, his brother-in-law, the inventor Albert Raynal manages to develop a revolutionary space rocket. Unfortunately, it fails on its test flight and Jérôme withdrew its financial support.