Writer Jason Aaron took the wheel on Marvel’s flagship Avengers series more than four years ago, and in that time Earth’s mightiest heroes have faced threats both terrestrial and cosmic across time and space. Aaron’s run is winding down now, and at SDCC this year Marvel announced that an event launching at the end of November will bring that run to a close. Avengers Assemble will see the two Aaron-written titles, Avengers and Avengers Forever, cross over for a story that brings the greatest heroes from across the multiverse together for one giant adventure. Aaron will team with all-star artists including Bryan HitchJavier Garrón, and Aaron Kuder for the storyline.

Here’s how Marvel describes the Avengers Assemble storyline, which will kick off with an Alpha one-shot in November and continue in the pages of Avengers and Avengers Forever in December:

From throughout time and the far corners of the Multiverse, the Mightiest Heroes of All the Earths are assembling as never before for a battle beyond all imagining. A war that will take us from the prehistoric beginnings of an Earth under assault by the greatest villains who’ve ever lived to the watchtower that stands at the dark heart of the all and the always, where an army of unprecedented evil now rises. The biggest Avengers saga in Marvel history is on the horizon and right now, fans can see how the story will unfold come December!  

In AVENGERS #63, it’s the showdown fans have been waiting for—THE BATTLE OF 1,000,000 BC! The Avengers stand face-to-face with their prehistoric counterparts, the Avengers of 1,000,000 BC! But if the two groups cannot work together, they have no hope of defeating Doom Supreme and his marauding band of Multiversal Masters of Evil, who have come to erase all of Marvel history as we know it..

In AVENGERS FOREVER #12, witness THE SIEGE OF INFINITY TOWER! The all Steve Rogers Howling Commandos. The interstellar air force that is the Carol Corps. The Star Panther. The God of Fists. The Invincible Ant-Man, Tony Stark. Together, they are the greatest army of Avengers ever assembled. But will they be enough to protect the Avengers Tower at Infinity’s End? Because Mephisto has come to claim that tower’s secrets, and he’s brought an army of his own.

In a statement announcing the two December entries, Aaron described the feeling of bringing his run on the Avengers to a close:

“Four years of Avengers stories. Threads from really every major series I’ve worked on throughout my last decade and a half at Marvel, from Ghost Rider to Thor. It all leads to this. The biggest Avengers story I could possibly imagine,” Aaron said. “Featuring a cavalcade of characters from across creation. And I’m so deeply thrilled and honored that it all kicks off with an oversized Alpha issue that’s being drawn by the legendary Bryan Hitch, who I’m getting to work with here for the very first time. Avengers Assemble. Say the words like a prayer. It’s the only thing that can save you.”

Jason Aaron has been no stranger to long runs on titles at Marvel, having previously helmed the adventures of Thor across a number of titles and events from 2012 until 2020. While his Avengers run is half that length, with eight times as many characters and an entire multiverse to cover we’re willing to cut him some slack there.

Look for Avengers Assemble Alpha #1 to arrive in stores on Wednesday, November 30th, with Avengers #63 out on December 7th and Avengers Forever #12 set to arrive on December 21st.