Cold sleep

"Cold sleep" is a popular term for true chemical or cryogenic suspension, aka "suspended animation". A reliable implementation of this technology has not yet been developed, and existing implementations frequently kill their target. Human testing of cold-sleep is illegal, as is any use of it. Despite that, rumors of this ability abound, and UNTIL is actively involved in researching this capability to hold dangerous criminals.

Various chemicals can reduce a person's vital signs to death point, hold them there, and return them, but there is the great danger of correct dosage and proper interaction with blood chemistry. No human tests have yet been conducted due to the above mentioned legal challenges.