Prelude: Book of the Skull
In the Egyptian desert, Sin and Baron Zemo seek out Sin's father's (The Red Skull) hidden journal about his greatest failure. After entering the base and recovering the book, Sin relates the story to Zemo:
In 1942, The Red Skull came across a gypsy camp and learned of a secret language that could summon a weapon from the gods. With the aid of the Nazi occult Thule Society, the Skull exterminated several Atlantean citizens as sacrifices for a ritual to summon this power. The process was seemingly successful, as a bolt of lightning landed in Antarctica.
The next day, Captain America, Bucky, and Namor come across the now-abandoned German castle, and find the dead bodies of the Atlanteans. They track down the Red Skull, who is already at the site of the crash. But the Invaders are attacked by a large blue demon that was apparently brought to Earth along with the weapon, by accident.
The Invaders defeat the demon, though the Skull manages to make his escape. Back at the crash site, the Thule Society occultists begin invoking special spells to protect and hide the weapon that fell from the skies - an Asgardian hammer. The journal of the Red Skull tells of this hammer's secret location.
Back in the present day, the secret base begins to crumble as a booby trap left behind by the Skull. Zemo and Sin escape out, but Sin betrays Zemo by shooting off his teleporting device, leaving him stranded in the desert while Sin leaves.
Book One: The Serpent
In Lower Manhattan, Steve Rogers and Sharon Carter attempt to calm down two sides of protesters arguing about whether or not there should be rebuilding at a 'sacred site' (implied to be Ground Zero). But the mob breaks into violence, and the entire crowd and the police get embroiled in a chaotic riot.
In Antarctica, Sin and her henchmen arrive at a secret base - the site where the hammer fell. The base is guarded by the Thule Society occultists, who have remained alive all these years through Nazi super-science. Sin and her troops forcibly break into the base, killing the scientists, and Sin finds the ancient hammer. She wields it, and becomes reborn and possessed by the power of Skadi - Herald of the Serpent.
Back at Avengers Tower in Manhattan, Steve Rogers is disappointed about the earlier outbreak of violence. Iron Man suggests to the entire team that they all stand beside him to announce the rebuilding of Asgard (which was destroyed in Siege) to create good publicity and faith in the Avengers.
In Broxton, Oklahoma - the site of the fallen Asgard - a civilian named Rick wishes his neighbor goodbye as the family leaves the town due to financial issues. At Asgard, Iron Man and the rest of the Avengers hold a press conference to announce the rebuilding of Asgard - funded by Stark Resilient and opening up jobs for nearly 5000 people in Broxton.
While Tony's speech goes on, Odin watches from a distance, and ominously says that they are doomed. The Watcher makes a sudden appearance, and Odin rants at him - asking if he has come to witness Odin's greatest failure - but the Watcher remains impassive and leaves. Thor finds his father, asking him to join the conference, but they get into an argument - with Odin saying that the city should be rebuilt in Asgard-space, not among mankind.
Deep in the Pacific Ocean, in the Marianas Trench, Skadi swims into a deep pit guarded by four giant serpents. She defeats them all and enters a chamber, where she comes face-to-face with the old Serpent for the first time. Back in Asgard, both Odin and Heimdall sense the return of the Serpent.
While the Avengers and the rest of the Asgardians are having a feast, Odin suddenly interrupts it and orders all of his people to return to Asgard-space. Thor tries to argue, but the father and son break into a physical exchange. Odin easily overpowers his son and strips Mjolnir from him, and then all the Asgardians depart from Midgard.
Elsewhere, the Serpent tells Skadi that they must turn the entire Earth into a planet of fear, and he summons the Worthy. From outer space, seven streams of light hit the planet and land in different locations.
Book Two: The Worthy
The Asgardians return to Asgard-space, and it is revealed that Odin has abandoned the Earth to the Serpent. Odin tells his people that he has fought the Serpent once, and that the enemy will create fear in the Earth and use it as its power source. He declares that the Asgardians have to purge Midgard in order to stop the Serpent. Thor confronts his father, but Odin easily creates a prison and orders his son imprisoned.
Back on Earth, in the supervillain prison known as the Raft, one of the streams of light hits it - revealing a hammer. Juggernaut approaches the weapon and touches it, transforming into Kuurth - Breaker of Stone. Similar impacts have occurred in China, the Pacific Ocean, Paris, and even New York. At the N.Y. site of Yancy Street, Reed Richards and the Future Foundation begin running analyses on the event.
In Brazil, the Hulk and Red She-Hulk investigate one of the crash sites, and the Hulk grabs the hammer that fell from space, transforming into Nul - Breaker of Worlds. In South Africa, Absorbing Man tries to lift another one of the hammers that landed, but is unable to. He notes that he couldn't absorb the hammer's properties. His girlfriend, Titania, successfully lifts it however...and is transformed into Skirn - Breaker of Men. Skirn tells the Absorbing Man that they have to go north to collect his hammer.
And in the Pacific Ocean, Attuma has found his own hammer and becomes Nerkkod - Breaker of Oceans. He begins destroying an oil pipeline. In Asgard, Odin and his people have started to build war machines for the razing of Earth. On the rest of the planet, the Worthy are rampaging and the entire Earth is thrown into fear and chaos.
But in the USA's capital of Washington, DC, Skadi and an army of Nazi mechs appear and launch an assault on the nation's capital.
Book Three: The Hammer that Fell on Yancy Street
Captain America (Bucky Barnes), Black Widow, and the Falcon mobilize to Washington to stop Skadi and her troops. Elsewhere on Earth, the rest of the Worthy continue their rampages, and in Brazil - the Avengers save Red She-Hulk from a mad Nul. On Yancy Street, the Thing grabs the hammer that landed there, and is transformed into Angrir - Breaker of Souls. He slams his hammer on the ground, destroying a large portion of the street.
In Asgard, the building of weapons continues, and Loki pays a visit to his imprisoned brother. With the help of some spiked food, Loki incapacitates the jailors and frees Thor. They meet with a number of Thor's friends who disagree with Odin and are plotting to save Midgard. Thor's allies tell him that Odin has sealed Asgard off, but that they have other means to spirit Thor off to Midgard to help rally the Earth's forces. But Odin learns of the meeting and interrupts it, and tells Thor that he doesn't know the threat he's facing, and that a prophecy is in the works.
Thor refuses to back down - asking for permission to stand with Midgard. Odin concedes to his request, and tells him that he has to stop the Serpent before the god reaches the World Tree in Oklahoma, or Asgard will destroy the Earth. Odin sends Thor back to Midgard, giving him back Mjolnir as well.
Back in Washington, Bucky is fighting Skadi, but she easily overpowers him and kills him - piercing his chest with her hammer. Captain America dies, his death marking the first casualty in the Serpent's War.
Book Four: Worlds on Fire
Just outside Broxton, Thor arrives on Earth, and is met by a group of local men armed with rifles. They are guarding the road into Broxton and tell Thor to move on - saying that they don't need the help of superheroes to protect their own people. The man known as Rick is among them. Thor flies off.
Around the world, the Worthy are creating fear and chaos, powering the Serpent and restoring his youth and energy. In San Francisco, the X-Men tackle Kuurth. In Paris, the Grey Gargoyle has found a hammer and been reborn as Mokk - Breaker of Faith. Nick Fury, Iron Man, and Widow gather around the fallen body of Bucky, and Thor meets them. Thor warns them that the Serpent strikes at man's fear, and feeds off humanity's emotions. He also tells them of Odin's plan to cleanse the planet by wiping out humanity. Nick Fury then tells Thor and Iron Man that they need to go and get Captain America.
The Big Three of the Avengers reunite in preparation for a counterattack. Captain America tasks Iron Man with building weaponry to fight against the enchanted weapons of the Worthy. Thor tells Captain America about the prophecy - that Thor is to slaughter the Serpent at the price of his own life. Cap replies that such a loss is unacceptable, and tells Thor to confront the Serpent, suggesting that the god of fear might be afraid of him if the prophecy is true.
In British Columbia, the dead bodies of Atlanteans begin floating to the surface due to the work of Nerkkod. This act provides the necessary power for the Serpent to summon his kingdom of fear - an army of giants as well as a city from Antarctica. Thor flies off to confront the Serpent, Iron Man heads to the site of fallen Asgard in Oklahoma, and Cap joins the battle against Skadi's army in Manhattan.
In Broxton, Tony sacrifices his sobriety as a petition to Odin - and tells Thor's father that he needs Asgardian workshops to build weapons for the Avengers. Thor confronts the now-young Serpent, but the god of fear teleports him into Manhattan...where he is confronted by Nul and Angrir.
Book Five: Brawl
In Manhattan, Captain America and the Avengers fight Skadi while Thor tackles Nul and Angrir. With regret, Thor kills Angrir - the Thing - by using Mjolnir to fly right through him. Thor then battles Nul and ends up using his teleportation powers to send the Hulk into space.The fight has left Thor severely weakened however, and he collapses due to his injuries.
But Franklin and Valeria Richards are able to find the dying Angrir, and using Franklin's reality-warping powers, succeed in restoring the Thing back to full health.
The Serpent and his floating kingdom make their appearance in Manhattan, and the Asgardian easily defeats the Avengers with a single hammer-strike. Captain America throws his shield at the Serpent, but the god of fear catches it and shockingly succeeds in destroying the iconic weapon. He then releases a huge burst of energy that levels a good portion of Manhattan.
A while later, the Avengers come to and Spider-Man requests for Cap's permission to run off and try to find Aunt May. Captain America allows him to, and forebodingly tells the rest of the Avengers that they are going to lose.
Book Six: Blood-Tied & Doomed
The remaining Avengers carry a defeated Thor to the ruins of Avengers Tower, where Heimdall's Observatory is. The New Avengers team, led by Luke Cage, agrees to stay back and help the evacuation of New York. While the main Avengers team travel to Asgard-space using the Observatory, in order to ask Odin to heal his son.
In Asgard-space, the Avengers appear in front of Odin, and Captain America verbally slams the All-Father - telling him to fix Thor. Odin teleports the Avengers back to Broxton, and tends to his son. When Thor has recovered, Odin bestows to his son his armor - the armor that Odin wore when he first razed the Earth in order to stop the Serpent the first time. He gives the suit of armor as protection, and also gives Thor the Odinsword, also known by its true name Ragnarok. Odin also tells Thor that the Serpent is his lost brother, and that he has tried to wipe the god of fear from Asgardian history.
In Svartalfheim, Tony (who has been busy building weapons for the Avengers with dark elves) meets with Odin and Thor. The weapons have Stark-tech and uru enchantments, and are designed to transform the Avengers into powerful warriors. The weapons are all thrown into a pit of boiling uru so Odin can bless them, and Iron Man jumps in with his Bleeding-Edge armor, to bless the suit as well.
In Manhattan, Spider-Man is searching for his Aunt May, and succeeds in finding her, but his aunt tells him to get back into the battle as it is his responsibility.
And in the ruins of Asgard in Oklahoma, Captain America heads out to the road barricade that the men of Broxton has set up. The floating kingdom of the Serpent approaches, and Cap makes his final stand while the rest of the civilians run away. On the kingdom, the Serpent has prepared for the final battle by re-gathering all the members of the Worthy (save for Nul and Angrir).
Book Seven: Thor's Day
The Serpent and his floating kingdom have arrived to use the site of fallen Asgard in Oklahoma in order to destroy the World Tree and eventually kill Odin. In the ruins of Asgard, Iron Man and Thor reappear, and begin arming the Avengers with their weapons. The Avengers armed with the Asgardian weaponry include Iron Man himself, Spider-Man, Hawkeye, Iron Fist, Black Widow, Dr. Strange, Wolverine, Ms. Marvel, and Red She-Hulk.
Elsewhere, the man known as Rick enters a shelter where his family (and others) are hiding, and he tells his wife that he's going back out there to help Captain America. He says that it wasn't right that they all (the men guarding the road barricade) abandoned Cap, and says that if this is the end, he doesn't want to be afraid anymore.
The final battle of the Serpent's War has begun. Thor charges towards the god of fear - who has transformed into a gigantic actual serpent - and throws Mjolnir. But the Serpent's flaming breath hurls the hammer aside, leading Thor to proceed to attack with Ragnarok.
On the ground, Captain America is fighting several of Sin's Nazi mechs with the aid of the newly-weaponized Avengers, and Mjolnir falls nearby, creating a huge explosion. Cap is temporarily stunned, but is helped to his feet, by Rick. Cap tells him that they're all Avengers now, and picking up the fallen Mjolnir, Captain America holds the hammer up in the air and yells, 'Avengers Assemble!'
The Avengers then get engaged in a final battle with the Serpent and his Worthy. As they do so, the tide begins to turn in the team's favor, and the fear in the entire planet begins to weaken as hope breaks through. Widow and Hawkeye tackle the Serpent's henchmen, Iron Fist and Strange take on Skirn, Red She-Hulk fights Nerkkod, Wolverine deals with Kuurth, and Captain America has a rematch with Skadi.
In Asgard, Odin prepares his armies to raze the Earth, as the Serpent has arrived near the World Tree. But just as Odin's armies appear, Thor succeeds in killing the Serpent by planting Ragnarok into the dragon's head. As fear subsides and hope builds around the planet, the Serpent and his Worthy have been defeated. Odin then uses his power to summon all of the Worthy's hammers to him, and he rushes towards his fallen son, who is dead.
One day later, on Saturday, the Avengers begin building a funeral pyre to burn Thor's body on the grounds of fallen Asgard. At the site of the battle, Captain America approaches Odin, who is by the corpse of the Serpent. Odin then casts all of the Asgardians out of Asgard-space and remains in there by himself, forever watching over the body of the Serpent.
On Sunday, Captain America and Widow attend the funeral of Bucky Barnes at Arlington National Cemetery. On Monday, in Svartalfheim, the dwarves there begin melting the enchanted weapons used by the Avengers, and one of the dark elves (Splitlip) present Stark with Cap's remade shield. On Tuesday, Tony presents the shield (which has now been made stronger with uru enhancements) to Cap, and offers to buffer down a scar on the shield. Cap says it's fine, and that the scar gives the shield some character.
On Wednesday, the Avengers begin the rebuilding of Manhattan. And on Thursday - formerly known as Thor's Day - Rick greets his new neighbor in Broxton. And a mysterious light is seen hitting the site of fallen Asgard...
These eight digital "exclusives" were later compiled into a print one-shot so they were taken out of the associated issues reading order, the print one-shot is #8 in the reading order.