Fallout 4 had a "BioShock-style vault" under the waves of Boston Harbor that never made it to the finished product, according to Todd Howard.
Howard revealed the new detail about the extremely well-documented game in a new Reddit ask-me-anything thread held in honor of Skyrim's 10th anniversary, where he also confirmed the Fallout TV show is still "moving ahead." Reddit user inexplicablehaddock (whose name is suspiciously well-suited to this question) asked about the original plans for Vault 120, an unused, underwater location referenced in Fallout 4's files. Howard's response was brief, but still enough to get us daydreaming about lighthouses again.
"Unfortunate cut content," Howard explained. "BioShock style Vault. With massive sentient octopus living outside it."
Vaults often serve as contained playgrounds for Bethesda to implement strange (and often terrifying) visions which have no business dwelling on the surface world - which is really saying something, considering the bizarre stuff you can find in any given corner of the Capital Wasteland and Commonwealth. It's easy to imagine the kind of pathos the studio could pack into a BioShock-style vault without even factoring in the kraken at its doorstep.
Would the massive, sentient octopus be a boss fight? Would you be able to defuse the situation with diplomacy? Would it join you in your undersea travels if your charisma stat was high enough? These are questions we may never know the answer to, at least not until Todd Howard does an AMA for Fallout 4's 10th anniversary.
Howard also kick started our dreams for Starfield mods by confirming plans for full mod support, despite the move to a new engine.