A humanoid people of the Lysian Alliance whom the Satarrans tried to destroy by turning a memory-wiped Enterprise crew against them.
The Lysians are humanoids of the Lysian Alliance, a power far less advanced technologically than the Federation. They were at war with the Satarrans.
In Conundrum, the Satarrans erased the memories of the Enterprise crew and placed an agent, posing as Commander Keiran MacDuff, aboard to convince them they were at war with the Lysians. The ship destroyed a Lysian vessel and approached the Lysian Central Command before Picard realised how weak their ships were, refused to continue and uncovered the deception.