"Interdimensional parasite. The passengers. Every parahuman has one, there's an extra organ in our brains making the connection. When I come up with some brilliant deduction, the computation's happening somewhere and it isn't in here. And when some cape sneezes plasma, that's not created out of nothing. The passenger moves things or energy or information in from parallel earths.

That's what Cauldron vials are, is a distilled connection to pieces of passengers."