Valerian et Laureline (english version) - Volume 15 - The Circles of Power

Broke, without a job, their ship almost a scrap heap, Valerian and Laureline
are stuck on Rubanis, unable to pay for repairs. So when a trio of old
acquaintances introduces them to the head of the local police, who is looking
for independent agents for a risky – but well-paid – mission, they accept
readily enough. But Rubanis is the most corrupt planet in the entire galaxy.
How are they to find out who really holds the reins of power there?