In discussion about Fallout 4 (and Fallout 5). One of the biggest DLC fumbles for FO4 probably of all time. For the canceled DLC “20 Leagues Under the Sea”.
20 Leagues Under the Sea would take place after completing “Here There Be Monsters” after repairing the Yangtze submarine. You would team up with Captain Zao and sail the submarine over to Vault 120, where the vessel would end up smashing into the sub bay of the Vault. The exact circumstances around the crash remain unknown. But given the amount of reference to Jules Verne and the presence of a sentient squid at the undersea Vault, it was likely that the octopod would play a major role, especially given that the squid would have been the overseer of Vault 120.
What exists has been reconstructed from game files that were accidentally left in Fallout 76.
I will always bring this up periodically for the insane potential this DLC had.