Hidden warehouse base
"I'm guessing extraterrestrial tech, but human-built," said Phantasma.
"...which, shockingly, fits my analysis as well," Kryten put in. "Which raises interesting questions. Isn't it supposed to be your government which has access to it, even in secret?"
"Yes," said Phantasma. "And that's a real mystery, because why would a government research project just randomly attack a mega-mart?"