*The only thing you really need to know is that people thought it was a good idea to let Norman Osborn basically be in charge of America, and he was juicing up Sentry with the serum that made him Sentry in an attempt to bring out Sentry's evil side, the Void. Apparently this was also a good idea at the time.
Also Asgard is on Earth and all the Asgardians are there.
The series begins with Loki and Norman talking about creating an incident with Volstagg, as he knows not of the Earth's ways like Thor.
The U-Foes attack Volstagg while he's in an Earth city and knock him into a stadium. Then they unleash their power and murder everyone in the stadium and disappear to make it look like Volstagg did it. Because all of the cameras and people who saw him get knocked away didn't see anyone else. This is also a repeat of what happens in Civil War with heroes getting blamed for villains doing the dirty deed (which you'd know if you came from the future and read my Civil War summary or whatever it was).
So now to the world it looks like some ginger obese man just murdered a stadium full of people for no reason. Norman now has a reason to invade Asgard and he gets a force together to do it. Norman tells everyone they're even if they help him murder a bunch of Gods, and that's enough. And Norman gets an army full of super villains to do it. Nobody bats an eye when Norman says they're going to murder a city full of GODS.
We're shown a scene where the president tries to get Norman to stop and says Norman is out of control. Which is shocking considering Norman was an outstanding fellow before hand with the rape and murders.
So Loki gives Balder a tiny warning, and then all of the sudden it's a full out attack with Sentry flying through the floating city of Asgard like a big yellow dildo, and a bunch of super villains right behind him.
Donald Blake sees this out the window and decides to turn into Thor as he leaps at Iron Patriot (Norman), then Sentry being the big yellow dildo he is rams Thor before he gets to him, and takes him a ways away. It's time for a huge showdown now!
Nope. Sentry gets one shotted.
Thor forgets his basic function of the hammer as a tool for absorbing or deflecting energy attacks, and takes a huge blast from numerous other super villains. Then he gets beaten down physically without lifting a finger. What a useless appearance for him here.
Ares and Balder are fighting, and then Heimdall comes out of nowhere and explains that Ares was fed a heavy dose of lies and then turns on Norman. Ares is terribly trustworthy in this series.
We cut back to Thor doing his best impression of a corpse as Maria Hill in a truck with a rocket launcher single handily blasts all the super villains away... which is just all the more hilarious considering how bad Thor did. Thor wakes up and hits Moonstone away, and that's all he did as they escape in a truck from numerous villains who can go supersonic... indicating two rockets from a rocket launcher are enough to completely deter like 20 high meta level enemies.
We're shown Cap assembling a weak group of heroes.
Ares turns on Norman and somehow jumps down on Norman when Norman was almost at the highest peak of Asgard already... Then Sentry coldcocks Ares with a big hit.
*You're going to want to skip to the next post here to get your official Siege companion food ready
Alright, Sentry is clearly going to just knock out Ares here. Real big deal here. Pretty serious looking fight though. Sentry really appears to be focused here. OK, Sentry gets sliced open and a big black tentacle comes out, that can't be good. Wait... wait... wait...
WHAT! Sentry just tore Ares in half. And it wasn't even like top and bottom, it was more like winning Connect 4 diagonally. His intestines and insides are spilling out. That is hilariously over the top.
Captain America and the heroes super travel to Asgard, which is kind of a minor detail considering what Sentry just did.
Then Daken is reporting to Norman about Thor when he gets fried to a crisp by Thor. "Good" everyone who read this comic said at the same time.
Cap smashes Iron Patriot with his shield and we have a good old fashioned hero vs villain brouhaha. Which at this point, we're led to believe that the rest of the Gods of Asgard are completely below a ragtag group of heroes hastily assembled by Cap. In a tie in, even Daken was slaughtering Gods. Asgard is nothing without Thor or Odin apparently.
Sentry then appears to a hurt Thor and says "How many Gods will I have to kill today?"
Quanchi had this as a sig.
Thor hits Sentry with his apparent rubber hammer he likes flaunting around all the time. Does nothing.
Then Norman orders some help from Loki, and Loki sends him The Hood (with the Nornstones) and the Wrecking Crew and some useless villains.
Speed (that's his ****ing name) then gives Tony a briefcase, and the president orders his jets to take down HAMMMER (Norman's version of SHIELD). We get some shots of the big war going on.
Thor then hits Sentry with lightning and red and black crab legs start coming out of him. God dammit
Norman gets beat up by Cap a bit until Tony appears and shuts down Norman's Iron Patriot armor.
Sentry's crablegs are then seen hugging Thor, and Thor is not the hugging type so he looks unsure of what to do. Norman then orders crablegs Sentry to bring down Asgard, and he stops sexually hugging Thor and takes down the floating city.
Asgard falls, and Thor says "No". Surprisingly Thor saying no didn't stop Asgard from getting destroyed.
The Iron Patriot armor falls off, and Norman is shown to have the Green Goblin face. Spider-Man punches him. He then goes crazy and says he was saving everyone from Sentry even though he pretty much forced Sentry to turn into what he is.
Sentry is now Mr Krabs
Mr Krabs is shown beating all the heroes including the weakened Thor. Loki realizing he just now made a mistake takes the Norn Stones away from The Hood, and amps all the heroes. Now all the heroes are able to cause decent damage to Mr Krabs. Thor destroys his body temporarily and Mr Krabs realizes something is up.
"Arg this is a trick to steal all me money isn't it boys?"
Then Mr Krabs realizes it's mischief and goes straight after Loki and murders him. All the heroes lose their amp due to the Nornstone user going down, but Thor is now back to full strength at least.
Thor now spams lightning like he's playing Marvel vs Capcom until he gets Mr Krabs out of the city. Tony turns a helicarrier into a bullet which is historically Sentry's weakness and it goes KABLOOEY right onto the Sentry. It was also pretty close to Thor, which considering how Thor liked to pretend he was a cadaver earlier, that was pretty risky.
Norman tries to get away in the confusion, but then Volstagg smashes him in the face.
Bob (Sentry's human form) is shown in the blast crater and he's naked having sex with the ground for whatever reason. Must have been the big cool explosion that made him stiff. He then politely asks Thor to kill him, which he refuses, so Bob turns into a huge version of Mr Krabs to politely get Thor to murder him, so Thor is like "alright fella, here comes my murder hit!"
"It had to be done" remarked Tony. So Thor throws his crispy ass corpse in the sun.
They then deal with all the villains, Cap is asked from the president to be Captain America, they have a big party, and Thor joins the Avengers. Everything worked out well in the end. Except for Ares, who died the most savage death I can think of in a comic event.
There's a tie in after this where everyone pretends Sentry was some great hero and he was the best person ever, also he had sex with Rogue before anyone even Magneto! He was the best guy ever, what a real standup dude. Recent and past events with the Void had no impact in what a magnificent guy he was! Awesome and such. There's not enough words to describe how cool and great he was.
And other shit like that.