Le Rayon U (The U Ray) is a comic book written and drawn by the Belgian comics creator Edgar P. Jacobs in 1943.
In 1941, the outbreak of war between Germany and the United States meant that American comic strips could no longer be imported into Nazi-occupied Europe.
Alex Raymond's strip, Flash Gordon, was then being published in the Belgian Franco-Belgian comics magazine Bravo. Artist and former opera singer, Edgar Pierre Jacobs was therefore asked to bring the current story to a satisfactory conclusion, which he did. He was then commissioned to produce a science fiction comic strip of his own. Le Rayon U ("The U-Ray") began serial publication in Bravo in 1943. This version had text boxes which described the action and the dialogues in the style of many Belgian comics of the time, similar in a way to Hal Foster's version of Tarzan and Prince Valiant.
In 1974 Jacobs reformatted Le Rayon U in order to include speech bubbles. This version was published in Tintin magazine and in book form by Dargaud-Le Lombard.
Le Rayon U is set on an Earth-like planet which combines elements of the distant past, present and far future. Two of its nations, Norlandia and Austradia, are in conflict. A Norlandian scientist, Marduk, has devised a weapon called the "U Ray", but requires a mineral called uradium in order to put it to actual use.
Marduk therefore organises an expedition into an unknown part of the planet in order to find the uradium. Those accompanying him include: his assistant Sylvia Hollis; the explorer Lord Calder; Adji, Calder's Indian manservant; and Major Walton and Sergeant Mac Duff of the Norlandian secret service.