Is that an African or a European sheep's bladder? I'm well aware of how dumb this sounds! But the fact remains, if I have a vial of Mysterious Serum in my inventory, my load times almost double. I remove it, they go back. I've tested it thrice; with all other factors remaining equal. I'm having the same problem i'm on the mission where you have to get those synths from bunker hill. If I fast travel I get an infinite loading screen. If I go into the basement to get the synths I get an infinite loading screen.