The mysterious Collector species is glimpsed so rarely as to be taken for a myth by most in galactic society. In reality, they are a terrifying force in the galaxy, responsible for the murder of hundreds of thousands. Seldom if ever seen outside the Terminus System, the Collectors have imprisoned entire colonies in stasis and their residents have disappeared without a trace of evidence. But that is not all Commander Shepard must face in his upcoming mission. The Geth return as well, and at their side is an elusive figure known only as Legion.