Inspired by H. G. Wells's novels The War of the Worlds and The First Men in the Moon, it follows the adventures of the eponymous scientist Doctor Omega and his companions in the spacecraft Cosmos.

The main protagonist, Doctor Omega, is the mysterious inventor of a projectile-shaped spacecraft dubbed Cosmos which can also function on land and under water.

It is made from a substance called stellite or repulsite (depending on the edition) which repels space and time and enables it to travel in the aether.

Doctor Omega and his two companions travel to Mars, where they first land in one of the Martian seas, where they perform some underwater exploration during which they encounter phosphorescent fish and aggressive reptilian mermen.

The book was later reprinted under the title Les Chercheurs d'Inconnu: Aventures Fantastiques d'un Jeune Parisien (Seekers of the Unknown: The Fantastic Adventures of a Young Parisian) as a 12-issue pulp magazine by Tallandier, Paris, Nos.

Frequent Doctor Who writer Terrance Dicks provided a foreword, and the cover illustration was changed to one similar to the 1973 Target Books novelization of The Daleks.

In 2009, French publisher Riviere Blanche reprinted the first edition, with selected illustrations from Bouard and Rapeno, a new foreword by Jean-Marc Lofficier, French translations of Terrance Dicks's foreword, and stories by Chris Roberson, Matthew Baugh, Travis Hiltz and Serge Lehman featuring Dr. Omega; cover by Gil Formosa.

Doctor Omega is mentioned and Tiziraou appears in a panel of The New Traveler's Almanac of The League of Extraordinary Gentlemen, Volume II.