The Commonwealth Story Expansion Project released Under The Stars, a new quest mod for Fallout 4 centered on exploring a mysterious bunker in the Glowing Sea. "The harsh radioactive winds of the Glowing Sea have uncovered a deep underground facility full of secrets and horrors," the group said in the mod's description.
The mod sends players in hazmat suits into a sunken bunker where they encounter voiced holotapes, puzzles, and new gear. Screenshots suggest the facility resembles Area 51 and contains evidence of aliens and other anomalies.
CSEP has released multiple Fallout 4 quest mods featuring deadly cults, underground wars, detective work, and Brotherhood of Steel storylines. Under The Stars was created for Fallout Flood, a community modding jam themed around underground locations. Other mods from the jam include Stranded - The Oasis for Fallout 4, a dungeon called S'Laven, a wearable robot enemy, and a New Vegas quest mod about an abandoned NCR railway.
The mod requires Fallout 4 along with the Automatron and Vault-Tec Workshop DLCs.