The season finale features possibly the biggest single lore reveal of the entire Fallout franchise, by depicting a meeting between two senior managers (including Cooper’s wife Barb) from Vault-Tec and representatives of corporations RobCo, West Tek, Big MT and Repconn. During this meeting, the Vault-Tec folks propose a collab: these companies help with Vault-Tec’s vaults, and in exchange they can do weird experiments on the people living in them and also be a part of Vault-Tec’s new world. And then Barb drops the biggest bombshell of them all: that Vault-Tec plans to start the nuclear armageddon themselves.

Both of these details are huge, because we never understood why so many of the vaults were so ridiculous and weird, and the games have always been intentionally vague about who sent the first nuke. Now we seemingly know both, though Barb making the proposal to drop a nuke doesn’t necessarily mean they followed through with it. But given the darkly funny nature of the franchise, Vault-Tec makes sense as the ultimate villain.

West Tek’s inclusion at the meeting is why I think Wilzig came from them–why would the Enclave have Vault-Tec’s cold fusion device? West Tek makes more sense, considering the Enclave is never mentioned again after episode 1, and never has any kind of presence on the series at all.