The Empire Of A Thousand Planets by Pierre Christin

Time-agents Valérian and Laureline are drawn into the politics and peril of a sprawling, authoritarian power that rules across countless worlds; as they navigate crowded alien metropolises, shifting alliances and a brewing resistance, they uncover a conspiracy that threatens interstellar order and must use wit, courage and diplomacy to expose and undermine the empire's mechanisms of control.

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