Mission: Countdown

Mission: Countdown Alpha, Mission: Countdown Bravo, and Mission: Countdown Charlie are repeatable main quests in Fallout 76.

Quick walkthrough
Before starting this quest you will need to acquire at least one nuclear keycard and the decrypted weekly launch code for the silo bunker that you intend to enter.

Once you enter a silo bunker (either Site Alpha, Site Beta, or Site Charlie), be prepared for many robot enemies. Bring energy resistance gear and energy weapons. Eventually you will need to enter a high radiation zone.