The Starbound Strings

A brown dwarf lies 1.5 light-years from the Solar System. It has three planets, one of which has developed a primitive civilization. Three hundred years ago, the Terman Corporation developed faster-than-light ships and led mercenaries in an invasion of the star system, founding the Terman Empire.

Three hundred years later, the Earth Federation establishes the Tiansha Guxing Extraterrestrial Exploration Team and sends a warship to the Oort Cloud, where it will uncover a history of civilizational invasion buried for hundreds of years...