This article deals with the code 0-8-4 objects. For the episode of the same name, see 1×02 0-8-4
Code 0-8-4 Devices refers to "objects of unknown origin" found littered throughout the world. According to international agreement, an 0-8-4 code allows S.H.I.E.L.D. to supersede all national claims to the object. A S.H.I.E.L.D. team will generally be dispatched to assess the 0-8-4, and then the object is either listed in The Index and sent to The Fridge for safekeeping, or, if the object is judged too powerful to risk being stolen, it will first be sent to The Slingshot to fake being destroyed, then subsequently returned to The Fridge to be kept in the lowest levels. Only on rare occasions are 0-8-4 objects allowed to be given to external claimants.
The 0-8-4 device in this episode is a Tesseract fuel cell built by Hydra during World War II and is powered by Tesseract energy. The device was discovered in Peru where it was retrieved by the Agent Coulson’s S.H.I.E.L.D. team and was delivered to The Slingshot to be "destroyed", and was then hidden in The Fridge. It was subsequently stolen by Hydra during The Uprising
The 0-8-4 in this episode was actually discovered 24 years ago in 1989, in the Hunan province in China. The team sent to investigate the 0-8-4 found out that it wasn’t a device but an infant girl that the entire Chinese village had died to protect. Whether she had any actual powers was unknown, but the first team started getting assassinated soon after taking custody of the infant. The Level 8 lead agent sustained a shot to the neck, but managed to make contact with the five back-up agents of the team with the infant before bleeding out. The five agents returned to the U.S. with the infant, but of the remaining agents, only Agents Richard Lumley and Linda Avery survived the continued assassination attempts before realizing they had to erase the infant from the system for all three to survive. The infant was left with St. Agnes Orphanage, and Agent Avery used the deceased Level 8 lead agent’s credentials to redact all information on the infant as well as clandestinely leaving an invisible protocol in the U.S. foster system, ordering them to move the child every few months to avoid detection. She was unfortunately assassinated shortly after placing the infant at the orphanage, and her only surviving partner, Agent Lumley, went into hiding for the remainder of his life, being the sole secret keeper of this mission.
edit] Other Appearances (Marvel Cinematic Universe)
The 0-8-4 device in this movie turns out to be Mjolnir, the legendary hammer wielded by Thor Odinson, who was unfortunately banished by his father Odin Allfather to Earth (Midgard) for stepping beyond his rank. Agent Coulson was sent to investigate the hammer’s appearance in New Mexico in 2011, as the hammer famously created a crater when it struck Earth, and no one, even with the assistance of various equipment, was able to lift the hammer. S.H.I.E.L.D. took charge of the perimeter around the hammer until it flew back into the hand of a changed Thor, who used it to reclaim his powers and destroy The Destroyer, which was trying to destroy the town of New Mexico. Mjolnir is listed in The Index, but its ownership remained with Thor.