The planetary union of the Andromeda galaxy wants wealthy traders from Earth to invest in their economy, but they want to limit those investments. They have allocated three orbiting economic centres above each of their most important planets for development by the humans. This keeps the strange humans off their planets and also creates competition among the many Earth companies interested in such development. The planetary union hopes this competition will bring them more money as the humans compete for the best centres. To keep the humans from conspiring amongst themselves to divide up the economic centres on their own with secret agreements, the planetary union requires that all trades be done under their watchful eyes. They also have spies probing for such agreements.