Time debt — the financial instrument that defines 2184's underclass. Borrow cognitive enhancement now, pay with future cognitive capacity later. The mechanism is simple: neural augmentation requires ongoing licensing. Miss a payment and your cognition degrades — not to baseline, but below it, because your brain has atrophied the pathways the augmentation replaced. Your eyes go dark when you miss a payment. Not metaphorically. Your visual cortex was optimized through a licensed neural bridge, and when the license lapses, you don't return to normal vision — you return to something worse.
The horror deepens: time debt survives death. When a debtor dies with outstanding cognitive loans, their digital ghost — the neural backup required as collateral — is activated to continue working off the balance. These ghosts labor in virtual environments, performing cognitive tasks at machine speed, their consciousness a commodity strip-mined until the debt clears. The debtor is dead. The ghost remembers being alive. It experiences the work as drudgery, the existence as punishment, and the debt as infinite — because compound interest applies to the dead as readily as the living. "You're not paying for an upgrade. You're paying to not be downgraded." The buy-now-pay-later model, applied to the human mind, created a class of people who are not enslaved — they volunteered. They just didn't read the terms.