Osiris was a wealthy world of the central planets. The seat of power on this planet was a city known simply as Capital City. Osiris was home to many rich and influential families, but as was often the case, a notable criminal presence had established itself in the planet's more urban areas. Criminals on Osiris were known to take advantage of "blackout zones", locations where monitoring devices were impractical and often malfunction. To combat this tendency, local security punished anyone found within a blackout zone with instant jail time, whether engaging in criminal activity or not.
This was the home planet of Simon and River Tam, and the Tam Estate was located also here. Osiris was the heart of the Alliance judicial system, and it was here that the High Court heard important cases.