Cryonics is the science of freezing living tissue for indeterminate periods before bringing that tissue back to life. In the mid 22nd century, Cryonics at last fulfilled its promise of safe resuscitation. This discovery spawned an interest from certain governments, as it could be used as a mean to separate criminals from the rest of the society at a minimal cost: they could simply be stored in a cryonic prison, and complete their sentences without bothering anyone else.