The Prince Baral asks for the help of Valerian and Laureline . He sends them on a mission to Bethel , a green world similar to Earth. If the planet is home to a sizable population, it could enter parliament galactic and tip the balance in favor of the Allies against the Vlagos Aldebaran. Our two heroes accept and take part in a convoy of immigrants on the planet Betel . Incognito, they fit in the group to expose the undercover agent Vlagos. This traitor aims to sabotage the operation.
