An uninhabited planet where Philippa Georgiou met the Guardian of Forever, disguised as a being called Carl, before leaving the 32nd century.
Dannus V is the uninhabited planet that Discovery's computer suggests could save the dying Philippa Georgiou in Terra Firma, Part 1. There Georgiou and Michael Burnham meet a strange being named Carl who directs Georgiou through a door that leads back to the Terran Empire of her past.
In Terra Firma, Part 2, Georgiou returns to Dannus V, where Carl reveals himself to be the Guardian of Forever. Having seen her try to change the Terran Empire's fate, he sends her through his portal to another time and place where she can survive.