Battle of Puente Antiguo

"Brother, whatever I have done to wrong you, whatever I have done to lead you to do this, I am truly sorry, but these people are innocent. Taking their lives will gain you nothing. So take mine and end this."

- Thor

The Battle of Puente Antiguo was fought between Asgardians Thor, the Warriors Three, Lady Sif, and the Destroyer. It was caused by the rivalry between Loki and Thor.

Background
Thor was exiled to Earth and Odin fell into the Odinsleep, making the only eligible temporary replacement as king Loki. Loki was a destructive king whose only plans were to get the love of Odin and to kill Thor.

The Warriors Three and Lady Sif, unhappy with Loki's rule, attempt to discover a way to end Thor's exile, convincing Heimdall, gatekeeper of the Bifrost Bridge, the means of traveling between worlds, to allow them passage to Earth. After their arrival, the four Asgardians were watched by S.H.I.E.L.D. agents, Cale and Garrett.

Battle
Thor rejoiced to see them, before they informed him that Odin was alive and that Loki was King. They saw another wormhole in the distance, and realized that Loki had sent the Destroyer after them.

Thor, Jane Foster, Erik Selvig and Darcy Lewis began to evacuate Puente Antiguo as the Warriors Three and Sif formulated a plan to stop the Destroyer. The Destroyer began attacking the town, destroying everything in its path, knocking back the Warriors Three before being seemingly stopped by Sif's Sword. However, the Destroyer simply rearranged its body to face Sif, seeming unstoppable.

Thor told them to fall back and that he had a plan. Thor approached the Destroyer and spoke to Loki through it, telling his brother that he was sorry but that he could not allow Loki to kill the innocent people, instead offering himself.

Loki seemingly relented before using the Destroyer to land a blow that would prove fatal to Thor in his unpowered form. Jane came to the dying Thor's aid, and sat with him before he died. Mjølnir then flew to Thor and returned his powers, as he was now made worthy by his sacrifice to others.

Thor, now fully healed and repowered, created a tornado around the destroyer and engaged it, deflecting its beams before disabling it. Thor then told the arriving Agent Phil Coulson that he must return Jane's research if he wanted his help in the future as they fought on the same side.

Thor promised to show Jane the Bifrost Bridge and flew her to the Bifrost site. Asking to open the Bifrost, Heimdall did not respond. The Warriors Three and Sif arrived, but he still did not reply. Heimdall eventually responded, and opened the Bifrost. The Asgardians returned to Asgard.

Aftermath
"We learned not only that we are not alone, we learned that we are hopelessly, hilariously, outgunned."

- Nick Fury

In Asgard, Thor flew to Odin's Chamber to see his mother Frigga and Loki, who was shocked to see him. Thor revealed Loki's deception. Loki said he did it all to impress his father and to be Thor's equal.

Loki also said he would destroy Jotunheim using the Bifrost Bridge and attacked Thor, who refused to fight his brother until Loki threatened to visit Earth and attack Jane Foster. Loki sent Thor flying through the wall of the chamber and headed to the Bifrost where he began the process of destroying Jotunheim. Thor flew to the Bifrost and engaged Loki where it goes to the Rainbow Bridge. Thor managed to hold Loki down by placing Mjølnir on top of him and went to stop the Bifrost, but it was too far gone to stop. Thor did not want to destroy the Bifrost because then he could not return to Earth to see Foster. But, for the sake of the Nine Realms, he called Mjølnir to him and began destroying the Rainbow Bridge, causing the Bifrost to fall away from Asgard in a mighty explosion and Thor and Loki were caught by Odin, who returned from the Odinsleep, and Loki revealed he did it all for him before letting go and falling into the abyss.

Back in New Mexico, S.H.I.E.L.D. Agent Phil Coulson and his team recovered the damaged remains of the Destroyer for study.

Humans, especially the World Security Council, realized that "we are not alone," and began building weapons to compensate for the threat of alien invasion, named Phase 2.

Trivia

 * There are deleted scenes of this battle where Thor healed Erik Selvig of a fatal injury he sustained during the Destroyer's attack, proving Thor was worthy of Mjølnir.