Where can I find the Hub mission in X3: Albion Prelude?

I'm looking for the Xenon Hub in X3: Albion Prelude. In what sector should I expect to find the Hub? Is there a mission that I should complete first? Where would I find it? Is there a minimum ship class that I would need first?

In order to acquire the Xenon Hub mini-plot, you must meet the following requirements:

• Started with the Albion plot enabled
• Completed the Albion plot
• Have a Boron rank of Queen's Guard (or higher)
• Found Atreus' Headquarters

If you have met those requirements, you should receive the following message:

This is an automated message offering you, an esteemed friend of the Boron, the opportunity to work for Atreus Shipbuilding Currents in Queen's Harbour. Please visit us to see what we can offer each other.

At which point you will need to travel to Atreus' Headquarters in Queen's Harbor to contact Gili Tosi.

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