A radioactive nebula hiding a dilithium planet, the stranded Kelpien child Su'Kal and the source of the galaxy-wide Burn.
The Verubin Nebula is where Paul Stamets and Adira trace the source of the Burn in Terra Firma, Part 1, using the SB-19 data. Discovery also detects a distress signal from a Kelpien starship inside it.
In Su'Kal, the crew finds a planet made largely of dilithium within the nebula, where a holographic simulation has raised the Kelpien Su'Kal. In That Hope Is You, Part 2, the crew learns that his anguish at his mother's death caused the Burn, and Discovery then begins carrying dilithium from the nebula to planets cut off for a century.