Appearing in "The Final Host"
- Avengers of 1,000,000 BC (Only in flashback) (Unnamed)
- Doctor Strange (Stephen Strange)
- Alpha Flight
- Ghost Rider (Robbie Reyes) (Possessed by Eli Morrow)
- She-Hulk (Jen Walters)
- First Celestial Host (Only in flashback)
- Eson the Searcher (Main story and flashback)
- Four unidentified others (Shadow only) (Only in flashback)
- Final Host of Dark Celestials (First appearance)
- Ghost Rider's new mammoth (First appearance) (Only in flashback)
- The Fallen (Mentioned) (Main story and flashback)
- Unnamed Homo erectus (Only in flashback)
- Hydra (Mentioned)
- Captain America (Steve Rogers) (Mentioned)
- God (Yahweh) (Invoked)
- Loki (Mentioned)
- Captain & Tennille (Mentioned) (Topical reference)
- Unnamed archaeologists (Corpses)
- Hoggoth (Invoked)
- Empirikul (Mentioned)
- Stark Industries (Mentioned)
- Starbrand (Kevin Connor) (Mentioned)
- Ymir (Invoked)
- Gammenon the Gatherer (Corpse)
- Arishem the Judge (Corpse)
- Oneg the Prober (Corpse)
- Numerous unidentified Celestials (Corpses)
Races and Species:
- Humans (Main story and flashback)
- Demons (Behind the scenes in main story and flashback)
- Mutants (Only in flashback)
- Abstract Entities (Only in flashback)
- Asgardians (Main story and flashback)
- Gods (Mentioned) (Only in flashback)
- Mammoths (Only in flashback)
- Homo erectus (Only in flashback)
- Celestials (Main story and flashback)
- Skrulls (Mentioned)
- Human-Kree Hybrids
- The Horde
- Dark Celestials (First appearance)
- Earth (Main story and flashback)
- Africa (Main story and flashback)
- North America
- Earth Orbit
- Hiroshima, Honshu, Japan, Asia (Mentioned)
- Center of the Earth
- Asgard (Mentioned) (Main story and flashback)
- Hell (Mentioned)
- Sun (Mentioned)
- Mjolnir (Only in flashback)
- Eye of Agamotto (Only in flashback)
- Starbrand (Only in flashback)
- Unidentified metal arm prosthesis (First full appearance)
- Captain America's Uniform and Shield (Main story and recap)
- Thor's golden hammer (First full appearance) (Unnamed)
- Iron Man Armor Model 4 (Recap)
- Doctor Strange's Cloak
- Panther Habit
- Hosts of Hoggoth (Invoked)
- Captain Marvel's Suit
- Hell Chain
- Jarnbjorn (Mentioned)
- Iron Man Armor Model 29 (Extremis Armor)
- Ragnarok (Mentioned) (Only in flashback)
- Super Bowls I-XL (Mentioned)
- Last Days of Magic (Mentioned)
Synopsis for "The Final Host"
On Earth, one million years ago, the Avengers (consisting of Odin, Ghost Rider, Black Panther, Lady Phoenix, Agamotto, Iron Fist and Starbrand) prepare to fight their greatest foe yet: the First Celestial Host. When Iron Fist asks Agamotto if they have a chance to win, the Sorcerer Supreme answers that depends on what she means: the life they are about to save (their own and that of the first forms of human beings) might very well be the end of Earth itself. As he argues they stand no chance against this threat, he concludes that maybe they should worry about what happens if they succeed in their goal.
On Earth, now, Thor, Tony Stark and Steve Rogers are having a drink together after a long time. Each of them has been through a lot lately: Tony was in a coma, Thor was deemed unworthy of his hammer, Mjolnir, and Steve was replaced by an evil version of himself. Steve brings up the idea of rebuilding the Avengers with them as the team's core, as it was in the past for years. Tony disagrees, since he believes the time has come for newer superheroes to take on this duty. Thor sides with Steve, arguing that the three of them need each other now more than ever. Just as Tony cries that now they only need a new calamity to fall on Earth to make it official, Motherboard (his new assistant A.I.) informs him of the detection of massive energy fluctuations in near-Earth orbit.
Meanwhile, two miles straight down, beneath the plains of South Africa, Doctor Strange and Black Panther investigate the remains of two archaeologists in a cave. Black Panther claims that what they discovered emitted an incredible amount of cosmic radiation, burning them alive, and he needs Strange's magic to identify what it was. Strange perceives a very ancient spell performed by Agamotto himself, which had lifted after the recent disappearance of all magic. The thing it used to contain is very large and stricken with fear. Black Panther then asks where it might have gone. The duo finds a series of holes digging further down towards the Earth's core. The thing couldn't have escaped there because of its size, but something else did, as T'Challa's probe went 200 miles deep and still going. T'Challa convinces Strange to follow him by saying that the symbols on the cave represent both their cultures (Wakanda and the Sorcerer Supreme's).
At Hillrock Heights, in East Los Angeles, when Gabe asks his brother Robbie Reyes, a.k.a. the Ghost Rider if he can take him on a ride on his car, the latter answers he needs to figure out some things first.
At the Alpha Flight Low-Orbit Space Station, the headquarters for Earth's planetary defense agency, Captain Marvel intends to explore the huge warp-holes that produced the energy fluctuations Tony was informed of. As she approaches it, she orders to sound every global alarm, as the hand of a Celestial warps out of it. Meanwhile, Tony, Steve and Thor are on a Quinjet to reach the crisis, while Strange and Black Panther reach a location, miles below the surface, where a heap of egg-like creatures lay. As the duo approaches, some of them open up, as bug-like monsters emerge out of them.
While Robbie screams at his car that he hasn't slept for days in order not to be teleported around the world after his fight with the Starbrand, some huge bug-like creatures emerge from the ground, forcing him to turn into the Ghost Rider to fight them.
Back in Manhattan, Steve, Tony and Thor reach Captain Marvel in an incredible scenery: a seemingly dead Celestial has landed on the coast of Manhattan. Tony asks Danvers if she did it, but she answers it was dead already when he came out of the portal. Not only that, there are hundreds more falling to Earth right now all over the world. As each Avenger tries to contain the crisis, and Tony asks what could've caused this, his question is answered with the appearance of huge, Celestial-like creatures: the Final Host. It is time for Cap to pronounce the famous words once again, after all: Avengers Assemble!
A NEW ERA DAWNS FOR EARTH’S MIGHTIEST HEROES – courtesy of JASON AARON and ED McGUINNESS!
Thor Odinson. Steve Rogers. Tony Stark. The Big Three of the Avengers are reunited at last! And just in time to save the world from total annihilation at the hands of their most powerful enemies yet: the 2000-foot-tall space gods known as Celestials. Behold the coming of the Final Host. Who will answer the call to assemble for a wild new era of Earth’s Mightiest Heroes? Hint: one of them has a flaming skull for a head. And what strange, world-shaking connection exists between the Final Host and Odin’s ancient band of Prehistoric Avengers?
- Legacy numbering is featured on the cover as "LGY #691" in the number box, continuing the previous volume's larger numbering. This numbering adds up various Avengers series as if they have never been relaunched.
- Four teasers were released online for this issue, which later became available as special character lithographs sold in conjunction with it.