Vault 199 (quest)

Vault 199 is an overseer quest and part of the A Wasteland Tail multi-stage questline in Fallout Shelter.

Walkthrough
After accepting the quest from the Overseer's office, your Dwellers will travel for eight hours. Following arrival, you will travel through the rooms, until you find a dweller, who informs you that Bigsby may be at Vault 899.