Chapter 4: Lady Sif

Two physicists, Jane Foster and Erik Selvig, and Darcy Lewis, an intern, are in the New Mexico desert, working from the van while conducting research on an aurora-borealis-type phenomenon. Suddenly a large tornado/lightning storm develops and they drive towards it to investigate. The van hits a man from inside the maelstrom and they stop. They find a woman, semi-conscious.

In Asgard, Odin describes a battle between the Frost Giants and Asgardians. The Asgardians win, take possession of the powerful Casket of Ancient Winters, and return to their realm. Odin is talking to his two sons, energetic Thor and a more thoughtful Loki. Odin says both of them are worthy but only one can be king of Asgard.

Thor, now an adult, prepares for a ceremony where he would be formally recognized as crown prince. Loki looks on enviously. Before Odin can follow through with the proclamation, he senses the presence of intruders. Three Frost Giants infiltrate the secure rooms that hold the Casket. However, the Destroyer appears and stops the intruders from reattaining the casket, killing all three. Examining the remains, Odin seems calm, yet Thor is angry and wants to attack. Odin disagrees.

Thor gathers Loki and his close friends, Volstagg, Fandral, Hogun, and Sif, and they ride out to the Bifrost Bridge. Heimdall allows them to pass and the six are transported to the Frost Giants' domain, Jotunheim, a frozen, crumbling wasteland. They confront Laufey who taunts the Asgardian warriors. More Frost Giants surround the six as Laufey allows them the chance to leave peacefully. But Loki that with an ancient artifact managed to hypnotize Sif and following the orders of Loki, she attacks Laufey and a battle starts. During the battle, Loki experiences an unusual reaction when he is touched by a Frost Giant.

Laufey releases a Frost Beast and the Asgardians retreat to the Bifrost. Thor kills the beast but once again the team is surrounded and things look ****. Odin arrives and intervenes to save the warriors, apologizing to Laufey for the intrusion and attempting to reinstate peace, but Laufey states that they are beyond reason, that the Frost Giants are now at war with Asgard. He attempts to stab Odin, who blasts Laufey back and takes the young Asgardians home.

Back at the Asgard side of the portal, Odin lets the four friends go and confronts Thor and Loki. Odin is furious with Loki and Thor for start a war with Asgard. Loki tries to calm his father but is quickly silenced. Odin strips Thor of his powers, banishes him to Jotunheim, and sends his hammer, Mjølnir to the Earth a few seconds later, saying, "Whosoever holds this hammer, if he be worthy, shall possess the power of Thor." Sif is sended to Earth too, because she was who start the battle.

On Earth, Sif (affected by the hypnosis of Loki) is immediately hit by Foster's van as they drive into the storm he emerged from. Sif faintly begins to question where she is and becomes aggressive to the point that Lewis tases him, knocking her out. The three scientists load him into their van and take her to the hospital. Once again he starts fighting as she wakes up and she is eventually tranquilized.

When the scientists return to their outpost in town they discover SHIELD confiscating all of their equipment and research in connection to the recent atmospheric disturbances, and the appearance of Thor's hammer. Unsure of what to do, the trio goes back to the hospital but Sif has escaped. As they drive off in the van, they hit the Asgardian woman again and knock her out, but this time they take hierwith them. Foster gives her civilian clothes that belonged to her. After overhearing locals discussing a satellite crash 50 miles due west, Sif decides to go there, and once again Selvig tries to get Foster to leave him alone. Sif walks about the town and tries to get a horse in a pet store. Foster appears and gives her a ride and the two head west in the van.

At the satellite crash site, a crowd of local townspeople has gathered; people are partying and trying to lift the hammer from the crater. Later, SHIELD arrives and takes over the site, setting up a temporary camp to study the hammer. After dark, Foster and Sif arrive on the scene. Sif infiltrates the encampment while Foster huddles in safety. After beating up many agents, and being targeted by the brainwashed agent of SHIELD Laura Barton (a command recruit her killing her husband Clint and hypnotizing them), Sif finally reaches the hammer but is unable to lift it. She don't resists the agents of SHIELD that jail her.

On Asgard, Odin falls into a coma-like state called the "Odinsleep", Thor comes back from Jotunheim and become king (wihout the modesty that he would learn in Earth if he would have been banished to Earth). He discover that Loki is the son of Laufey and furious, decided kill him..

Back on Earth, agent Jasper Sitwell questions Sif, and when she leaves her alone briefly, Loki appears in the room and makes that she come back to her trance. He order she kill Selvig and use the ancient artifact to hypnotize Jane Foster and Darcy. Selvig, with a faked driver license, arrives and lies to the S.H.I.E.L.D. agents, telling them that Sif was an intern of Jane Foster. Sitwell lets Selvig take Sif, who surreptitiously grabs Foster's notebook on the way out. Back in town, Selvig takes Sif out for a drink, now trying to convince Sif to leave Foster alone due to the complications he has and would continue to cause her, but Sif, following the orders of Loki, kills him and bury his body in the dessert. She comes back to Foster's trailer and hypnotize Jane and Darcy, telling them that now must obey Loki, explaining the Nine Realms and the Bifrost Bridge to them. Jane figures the bridge is the theoretical Einstein-Rosen Bridge wormhole, the very same that she has been researching.

Thor knock out Heimdall and uses the Bifrost to meet with Laufey. He pretend make a deal with Laufey that he will let them into Asgard again to kill Odin and have their casket, and in return, they will return home in peace. Thor then commands the Three Warriors and the Destroyer to go to Earth and kill Loki and bring back lady Sif.

The Destroyer arrives in the New Mexico desert and starts blasting everything with a heat ray. The hypnotize Sif, Jane and Darcy attempt to get everyone away safely. Sif confronts the Destroyer and sacrifices to protect Jane and Darcy. The Destroyer gives Sif a vicious backhand slap and sends her tumbling, apparently dead. However, Sif's selfless act of protection proves her worthy to once again wield Mjølnir, which frees itself from the crater and comes to Sif's hand. (All was a plan to Loki to cheat the magic of the hammer) Sif is restored to full life and obtained the powers of Thor. She easily defeats the Destroyer. Loki and Sif comes back to Asgard, but Loki command Jane Foster and Darcy that they will be his sleepers agents in the Earth.

The Frost Giants invade Asgard through the portal, walking past the **** Heimdall. Laufey goes to Odin's bedchamber and, as he prepares to kill the Norse god, but all was a trap from Thor to kill the Frost Giants leaders. Heimdall recover his conscious and seeing that Thor wasmaddened by power and bloodlust brings Loki and Sif back to Asgard. Sif and Loki flies quickly to fight the Frost Giants.

Thor goes to the Himinbjorg and sets the bridge up to destroy the ice planet Jotunheim. Loki and Sif tries to stop him and the two engage in combat. Sifimmobilizes Thor with Mjølnir and starts to destroy the Rainbow Bridge to stop the portal. When the bridge shatters, Sif and Thor fall into space but Odin arrives and catches Sif, who holds Thor's staff. Thor, not being able to bear having lost his father's favor admits defeat and allows himself to fall, disappearing into the void.

All seems back to normal on Asgard, although Odin is saddened by the turn of events. Loki, now as inheritor of Odin and in a relationship with Sif, is upset for the destruction of the Raimbow Bridge, delaying his plans to take Earth and he suspects that Heimdall distrust him, but he knows that his sleepers agents, the hypnotized Jane and Darcy are in a new lab with new equipment, now being assisted by S.H.I.E.L.D.

Afterwards, Jane has been taken to the Joint Dark Energy Mission Facility where she meets Alexander Pierce. Pierce shows him the Tesseract in a briefcase, which he says could be a source of unlimited power. Thor, disguised as a agent shield named Donald Blake, believe that this is the object that he needs to take **** on Loki.