Tesseract

"He thought what we think; the Tesseract could be the key to unlimited sustainable energy. That's something the world sorely needs."

- Nick Fury to Steve Rogers

The Tesseract, also called the Cube, was a crystalline cube-shaped containment vessel for the Space Stone, one of the six Infinity Stones that predate the universe and possess unlimited energy. It was used by various ancient civilizations before coming into Asgardian hands, kept inside Odin's Vault. Eventually, it was brought to Earth and left in Tønsberg, where it was guarded by devout Asgardian worshipers.

In 1942, the Tesseract was retrieved by Johann Schmidt, the leader of HYDRA, who used the Tesseract to power enhanced weaponry in order to defeat the Allies during World War II. Following Schmidt's defeat at the hands of Captain America in 1945, the Tesseract fell into Arctic waters, where it was recovered by Howard Stark. The Tesseract was then kept at Camp Lehigh in New Jersey, where it remained until at least 1970.

Spending decades attempting to harness its power, Stark eventually helped found Project P.E.G.A.S.U.S., to whom he relinquished custody of the Tesseract in the 1980s. Mar-Vell, an undercover Kree, joined P.E.G.A.S.U.S. and harnessed the Tesseract's power to create the Light-Speed Engine to assist the Skrulls in their war against the Kree and took possession of the Tesseract, storing it in her laboratory in orbit. In 1989, Yon-Rogg killed Lawson, causing pilot Carol Danvers to destroy the engine, as she was doused in Tesseract energy. Six years later, Danvers recovered the Tesseract from Lawson's laboratory and relinquished custody of it to S.H.I.E.L.D.

It remained in their possession until 2012, when it was stolen by Loki who used the Tesseract to open a wormhole and allow the Chitauri to invade New York City. Following the Battle of New York, the Tesseract was acquired by Thor, who brought the Tesseract and Loki back with him to Asgard.

After using the Tesseract to repair the Rainbow Bridge, Odin tasked Heimdall, the realm's gatekeeper, with the task of protecting the Tesseract. However, after Loki usurped the throne and disguised himself as Odin, he charged Heimdall with treason, forcing the gatekeeper to flee, while the Tesseract was placed within Odin's vault once more.

During the destruction of Asgard, Loki noticed the Tesseract and took it for himself before the vault, along with the planet, were destroyed. Thanos later acquired the Tesseract and crushed it to unveil the Space Stone within and then inserted the stone into his Infinity Gauntlet.

Origins
In the wake of the universe's creation, the six singularities were forged by the Cosmic Entities into the Infinity Stones. The Tesseract was created as a containment vessel for the Space Stone. Within the Tesseract, the Stone was owned and used by various civilizations to achieve their ends.

Ancient Times
"The Tesseract was the jewel of Odin's treasure room."

- Johann Schmidt

The Tesseract came to be kept in the care of the Asgardians during Odin's rule, locked away in Odin's Vault. The Tesseract was brought to Earth by Odin and after being left on the planet, it ended up being kept safe in a church in the village of Tønsberg. The Tesseract became the subject of many legends of Norse mythology.

World War II
"The energy we have just collected could power my designs. All my designs. This will change the war." "Doctor Zola, this will change the world."

- Arnim Zola and Johann Schmidt

In March 1942, during World War II, HYDRA forces led by Johann Schmidt invaded Tønsberg where he found the Tesseract in a box hidden behind a sculptured mural of Yggdrasil, the world tree. Schmidt took the Tesseract back to HYDRA Headquarters to be the subject of experiments by Arnim Zola. After experimenting on the Tesseract, Schmidt and Zola were able to harness the object's power to create highly advanced weaponry, fueling Schmidt's plans for world domination.

Zola created batteries that contained the power of the Tesseract, which were then used by Zola and a handful of HYDRA scientists to power their weaponry. With the power of the Tesseract, Schmidt felt strong enough to turn his back on Adolf Hitler and the. He intended to destroy both the Axis and Allied powers and make himself ruler of the world. In November 1943, Schmidt brought the Tesseract into HYDRA's top secret weapons facility in the Austrian Alps, located halfway between and. While the facility was in operation, Allied Prisoners of War were forced to serve in the large-scale assembly of Tesseract-based energy weapons, including the Valkyrie super-bomber, and a set of nuclear-scale Tesseract energy bombs. When the Allied super soldier Captain America infiltrated the facility to free the four hundred Allied POWs, a large confrontation began. Seeing that his men wouldn't be able to defeat the freed prisoners, Schmidt took the Tesseract and set the base to self-destruct. In March 1945, with his gigantic super bomber, the Valkyrie finally finished, Schmidt was prepared to launch an offensive that would shake the entire planet. With its flying nuclear bombs, Schmidt intended to destroy populated cities across the United States. However, his last base was attacked by Rogers, the Howling Commandos, and a United States Army division led by Chester Phillips and Peggy Carter. Schmidt's men were defeated, but he managed to take the Tesseract and launch the Valkyrie. However, Rogers managed to board the plane and attacked Schmidt, damaging the machine that was using the Tesseract to power the Valkyrie and its flying nuclear bombs. Angered, Schmidt grabbed the Tesseract, only for the object to open a portal which transported him to Vormir where he became the keeper of the Soul Stone. The Tesseract fell to the plane's floor and, super-heated with energy, burned through the fuselage, causing it to plunge into the sea below. Sometime later, it was recovered by Howard Stark who was searching for Rogers.

A group of former HYDRA scientists managed to escape to South America where they were employed by the government of Peru to make a powerful weapon while using Zola's discoveries of the Tesseract's energy. The scientists were successful, but because the Tesseract's energy was unstable, the weapon ended up stuck in an undiscovered Incan temple.

Project P.E.G.A.S.U.S.
"Is that it? The core?" "In her notes, she called it the Tesseract."

- Maria Rambeau and Carol Danvers

Following the war, Stark studied the Tesseract for some time, recording his research in a notebook. Stark and S.H.I.E.L.D. had the Tesseract relocated to Camp Lehigh in New Jersey, where it remained in storage for many decades. Believing that the energy within the Tesseract would be beneficial to mankind, Stark was instrumental in the creation of Project P.E.G.A.S.U.S., a joint venture between S.H.I.E.L.D., NASA and the United States Air Force tasked with studying and harnessing the Tesseract's energy. Stark relinquished custody of the Tesseract to P.E.G.A.S.U.S. The Kree scientist Mar-Vell, who had taken on the guise of a human and was calling herself Doctor Wendy Lawson, joined the project with the goal of harnessing the Tesseract's power to create a Light-Speed Engine for the Skrull refugees under her protection. The Tesseract was eventually relocated to Mar-Vell's orbital laboratory, where it remained untouched for six years. When Carol Danvers and Nick Fury arrived at the lab, they placed the Tesseract in a  lunchbox, attempting to smuggle it out before the Starforce arrived, demanding the artifact. Goose, a Flerken, swallowed the Tesseract while Danvers led her former allies on a diversionary chase for the empty lunchbox. Once the Kree and Skrulls had left Earth, Goose regurgitated the Tesseract on Fury's desk.

In the Possession of S.H.I.E.L.D.
"We'd like to have an open discussion regarding the primary objective of S.H.I.E.L.D. as an agency and of you as its director." "You're talking about the Tesseract." "Reigniting the Tesseract. That is correct."

- World Security Council and Nick Fury

Following its regurgitation, the Tesseract returned to S.H.I.E.L.D.'s possession with the World Security Council ordering S.H.I.E.L.D. to use the cube to develop advanced weapons and better defend the Earth from any alien threats.

After the Battle of Puente Antiguo in New Mexico during which Thor defeated the Destroyer, humanity finally realized they were not alone in the universe. Erik Selvig was assigned by Fury to research and study the Tesseract with hopes of unlocking its power just as Schmidt had. Later, the Tesseract was moved to the Joint Dark Energy Mission Facility in the Mojave Desert, where Fury also positioned Clint Barton to keep guard over Selvig and the Tesseract.

War for Earth
"I have seen the true power of the Tesseract, and when I wield it–" "Who showed you this power?"

- Loki and Thor In 2012, Loki came into contact with Thanos, powerful warlord and the master of Chitauri. Thanos had already been seeking the Tesseract in order to retrieve the Space Stone, and Loki promised to retrieve it from Earth and give it to him in exchange for his army. Through manipulation of the Tesseract's energy, Thanos teleported Loki to the Joint Dark Energy Mission Facility where he killed several S.H.I.E.L.D. agents and enthralled Erik Selvig, Clint Barton, and other agents.

Loki revealed his plans to use the Tesseract to enslave and rule over the human race, stole it, and escaped. The energy from the portal destroyed the facility, while Loki took the Tesseract to an undisclosed location.

In response to Loki's threat, S.H.I.E.L.D. decided to re-start the Avengers Initiative and swayed Bruce Banner, Iron Man, and Captain America to their cause. Nick Fury also wanted them to trace the Tesseract as it was emitting small amounts of Gamma Radiation that only Banner and Stark would be able to trace. While Loki was dealing with the Avengers, he ordered Selvig to begin working on a device that could utilize the Tesseract's full power to create a portal that could transport the Chitauri army to Earth. Selvig and Loki later put their plan into effect and opened the portal above Stark Tower in New York City, which unleashed the Chitauri upon the city and an immense battle ensued. Eventually, Black Widow used Loki's Scepter to reverse the effects of the device, shutting down the Tesseract and closing the portal. Following the invasion, Thor returned Loki and the Tesseract to Asgard. Though the World Security Council disapproved, Fury defended his decision to allow Thor to take the Tesseract to Asgard, saying that humanity was not ready for the Tesseract's power, much to the council's dismay.

Back on Asgard
"Take the Tesseract. Use its power instead of the All-father's to restore what I have destroyed. Let the fires of Bifrost burn once more..."

- Thor to Heimdall After his return to Asgard, Thor gave the Tesseract to Heimdall. The all-seeing Asgardian used the Tesseract to repair the Bifrost Bridge so the Asgardians could once again protect all of the inhabitants of the Nine Realms endangered by the Marauders. Later, the Tesseract was locked in Odin's Vault so no one could use it again without Odin's permission. Hela noticed the Tesseract as she was walking in the vault, and she admitted the power of the cube. During Ragnarök, when Loki was about to resurrect Surtur in order to defeat Hela, he decided to take the Tesseract before also taking the Crown of Surtur.

Destroyed by Thanos
"We don't have the Tesseract. It was destroyed on Asgard."

- Thor to Thanos

Having located the Tesseract on the Statesman, Thanos and the Black Order traveled with the Sanctuary II and attacked the ship. They killed half of the Asgardian survivors and captured Thor and Loki. Thanos tortured Thor with the Power Stone in order to make Loki give him the Tesseract. Loki acceded to his demands, though he managed to stall long enough for Hulk to ambush Thanos. But Hulk was swiftly defeated. Afterward, Ebony Maw retrieved the Tesseract and presented it to Thanos, who proceeded to effortlessly crush the Tesseract in his hand and placed the Space Stone in his Infinity Gauntlet.

Time Heist
"I'm going to need that case. It's been S.H.I.E.L.D. property for over 70 years."

- Alexander Pierce

In an attempt to reverse the effects of the Decimation, Tony Stark, Scott Lang, Bruce Banner and Steve Rogers traveled back in time from 2023 to 2012, to retrieve the Tesseract.

The Tesseract was to be taken back to Asgard by Thor after they had apprehended Loki. However, Alexander Pierce demanded that the Tesseract, having been S.H.I.E.L.D.'s property since 1945, should be kept in their custody along with Loki.

During a short argument, Ant-Man temporarily disabled the younger Tony Stark's Arc Reactor causing a cardiac arrest and distracting everyone in the room. In the middle of the commotion, Ant-Man and the elder Stark attempted to retrieve the Tesseract but were accidentally attacked by the 2012 Hulk, causing the Tesseract to fall into Loki's possession and allowed Loki to immediately use it to teleport himself away.

This forced Stark and Rogers to travel further back in time to April 7, 1970 to retrieve the Tesseract along with more Pym Particles from Camp Lehigh in New Jersey. The Tesseract was taken from a S.H.I.E.L.D. lab by Stark and was kept hidden until Stark and Rogers could travel back to 2023 to extract the Space Stone from it. After finishing their mission, Rogers returned the Space Stone to the base in 1970.

Capabilities
"If there was any tampering sir, it wasn't at this end." "At this end?" "Yeah, the cube is a doorway to the other end of space right? Doors open from both sides."

- Clint Barton and Nick Fury The Tesseract is a cube which contains an Infinity Stone, representing the fabric of space. If used correctly, the Tesseract can open gateways to any part of the universe and provide interdimensional travel. Taking the Tesseract physically, Red Skull was suddenly transported to Vormir where the Soul Stone chooses him as a Stonekeeper. Thanos was able to manipulate the Tesseract from afar to open a portal that transported Loki to the Joint Dark Energy Mission Facility, which destroyed the facility. With its power, Erik Selvig was able to construct a device that opened an enormous portal to the Chitauri.

Many believe it is an unlimited source of energy because it draws cosmic energy from space. It appears to possess intelligence, or will; when Erik Selvig was studying it, he noted that it "behaves" as though it has awareness. When the power used to harness its energy is cut off, the Tesseract turns the power back on. The Tesseract was able to recognize Schmidt as "unworthy" to possess the space stone within, which is why it opened the portal to Vormir. The exact source of its cosmic power is not known, but the Tesseract apparently can be manipulated from that endpoint as well. The Tesseract emitted low levels of Gamma Radiation, which interfered with Selvig's methods to harness its energy source, and later allowed S.H.I.E.L.D. to track its movements.

As a power source, it can be used to power objects and artifacts of incredible scale, such as the Bifrost Bridge. A single spark of its power was enough to create a small explosion. When Mar-Vell's Tesseract-powered light-speed engine exploded, the released cosmic force imbued Carol Danvers with the ability to manipulate energy itself. She could, for example, use energy to propel herself through the air, and emit energy blasts from her hands. HYDRA was able to use the Tesseract to power advanced vehicles and weapons of mass destruction including guns, tanks, and bombs that vaporized their targets. It melted through steel on contact, although it could be held using gloves for a short time, or when handled in special containment units. It could also be handled directly by exceptionally powerful beings such as Captain Marvel, Goose, Loki, Ebony Maw, and Thanos.

Tesseract Energy
"I think, well, I'm most likely dead on that the Tesseract energy excites plasma with an inverse population of energy levels." "A laser." "A ray of pure energy, two terajoules."

- Leo Fitz and Jemma Simmons Many people have tried to duplicate the type of energy that the Tesseract emits. The only people that are known to have successfully harnessed the Tesseract's energy were Mar-Vell, Johann Schmidt and Arnim Zola. Zola developed a method to siphon off and store its energy with a Tesseract Battery to power weapons. Former HYDRA scientists were able to replicate the power of the Tesseract and create a powerful laser weapon for the Peruvian government. Mar-Vell developed the Light-Speed Engine using the energy of the Tesseract to help aid the Skrulls in ending the Kree-Skrull War. When the Light-Speed Engine exploded, Captain Marvel absorbed the energy of the Tesseract and gained cosmic powers. Howard Stark discovered a way to make an element with a similar type of energy, but because of the technological limitations of his era, he was not able to bring his discovery to fruition. Years later, Tony Stark was able to make the element based on his father's research. The element was used as the core for a new Arc Reactor that would stop Stark's palladium poisoning.

Trivia

 * In the non-canon video game Captain America: Super Soldier, the Red Skull uses the Tesseract to activate the Sleeper, the giant robot buried beneath Castle Zemo.
 * In the comics, the Cosmic Cubes are cube-shaped matrices that can control matter and energy, and allow their users to shape reality. The cubes were used by different species, like the Beyonders, the Kree, the Skrulls and Humans like Red Skull and A.I.M. members.