S2, E20: When an alien attacks National City, Supergirl and the DEO learn the alien is a Phorian, an otherwise peaceful race with telekinetic powers. Guardian gets a lead on the Phorian's location but instead of finding the culprit, he finds a very scared boy named Marcus (guest star Lonnie Chavis). Marcus will only trust James, so it is up to Guardian to stop the attacks on the city. Meanwhile, Rhea's plan escalates.