An uninhabited burial planet that held the first piece of the map leading to the Progenitors' technology.
Lyrek is the uninhabited burial planet that Discovery visits in Under the Twin Moons, guided by images of the Romulan journal recovered from the android Fred. Michael Burnham and Saru, on his last mission before becoming a Federation ambassador, transport to the surface and disable an automated defense system with an electromagnetic pulse.
They find a piece of the map left by the 24th-century scientists who hid the Progenitors' technology, and they learn that the next clue lies on Trill even though Moll and L'ak are heading for Betazed.