The last movie set within the DC Extended Universe is Aquaman and the Lost Kingdom, continuing the epic story from the enormously successful 2018 film Aquaman. Ahead of the movie’s premiere, the gap between the 2018 film and its upcoming sequel is filled by the official tie-in comic book Aquaman and the Lost Kingdom Special. Written and illustrated by fan-favorite creative teams, the special significantly advances the plot and major character arcs that are sure to pay off in a big way when the movie opens in theaters this December.

Here are the biggest plot developments in Aquaman and the Lost Kingdom Special, where the main characters are positioned by the end of the comic issue, and what fans can expect from the movie based on the comic’s story. Spoilers below.

A royal wedding

Even with Ocean Master defeated, ending his bid to attack the surface world and conquer the rest of the seven kingdoms, there is still plenty of tension in the resulting peace. In the special’s lead story, by Tim Seeley and Miguel Mendoça, Arthur’s mother Atlanna hopes for a public wedding in Atlantis to remind the seven kingdoms what they are peacefully capable of in standing together, but Arthur and Mera are less than enthused. After Atlantis weathers an attack from the monstrous Charybdis, this plan is quietly discarded.

Instead, the wedding is held at Amnesty Bay, within view of the Maine lighthouse tended to by Arthur’s father Thomas Curry. Attending the wedding is Thomas, Atlanna, and a small continent from Atlantis, with Mera’s father King Nereus presiding over the ceremony. Afterwards, the wedding party relocates to celebrate at Terry’s Sunken Galley, the dive bar frequented by Thomas and Arthur, with Atlanna drinking her newlywed son under the table.

A baby on board for Aquaman and Mera

In the days leading up to the wedding, Mera exhibited a heightened amount of anxiety, with Arthur afraid that she was having second thoughts about their impending nuptials. Compounding this, Mera stayed behind, leaving Arthur and Vulko to fight Charybdis without her, even with the fate of Atlantis hanging in the balance. Shortly after the wedding, Mera confides in Arthur that she has been pregnant with their child for some time.

Early promotional materials from the film Aquaman and the Lost Kingdom confirms that Arthur and Mera have since had a son together, named Arthur, Jr. By the start of the movie, Arthur, Jr. still appears to be an infant, cared for by his loving parents. However, as with the comic book source material, Arthur, Jr. may be targeted by a familiar foe who shows up in both the movie tie-in comic and upcoming cinematic sequel: Black Manta.

The rise of Black Manta

The mid-credits scene for 2018’s Aquaman saw the origins of an alliance between the villainous Black Manta and scheming scientist Stephen Shin. A story in the special by Joey Esposito and Ray-Anthony Height, this partnership is still very much active and growing as Black Manta continues to build his vengeance against Aquaman for the death of his father in the original film. Manta travels the globe honing his skills to become the ultimate killing machine, with the single-minded drive to kill Arthur Curry and everyone he cares for.

More than just improving himself, Manta begins building an army of his own, starting with a pirate crew linked to his father’s illicit past on the high seas. Brutally dispatching the opposition, Manta gives the crew an ultimatum to join him or die, with many of the pirates deciding to give him their unwavering loyalty. Now that Black Manta's in possession of technology that allows him to venture to the bottom of the ocean, nowhere and no one will be safe from his wrath.

Ocean Master no more

Black Manta isn’t the only supervillain who’s followed up on in the special, with Arthur’s megalomaniacal half-brother Orm starring in a story by Ethan Sacks, Scot Eaton, and Norm Rapmund. In the 2018 movie, Orm tried to subjugate the seven kingdoms to recognize his rule of the oceans and attacked the surface world with a tidal wave in an overwhelming show of force. Defeated by Aquaman, Orm was spared by his half-brother and jailed for his crimes after plunging the seven seas into open war.

The special picks up with Orm locked away for several months, feeling that his punishment is an unjust one denying him of his rightful claim to the Atlantean throne. Orm is routinely beaten by the guards and his fellow inmates, all while patiently biding his time as he plots his escape and renewed push to seize control of Atlantis. However, for as meticulous and calculating as Orm is, he finds the guards are unfazed by even his most thought-out schemes and resigns himself to the possibility that he may not escape after all.

A fragile future for Atlantis

Arthur and Mera’s wedding, while certainly a joyous occasion for all parties involved, was not the harmony-affirming, unifying event that Atlanna had hoped for, leaving deep-seated tensions between the kingdoms and surface world. This, of course, doesn’t even account for the impending threat that Black Manta intends for Atlantis, nor the destabilizing potential that Orm presents within the undersea dungeons. And amidst all of this underwater intrigue, the special takes the time to introduce a new supervillain who may resurface in Aquaman and the Lost Kingdom: Charybdis.

Blaming Aquaman for the death of his beloved Scylla, Charybdis transforms into a monster that shakes Atlantis to its foundations. Aquaman defeats Charybdis and convinces him to retreat, but the enemy remains very much alive and presents a risk to Atlantis’ wellbeing. The greatest cost from this initial showdown with Charybdis is Arthur’s trusted advisor Vulko, who is gravely wounded. This comes in the wake of Willem Dafoe not expected to reprise his role as Vulko in the upcoming film and could explain the character’s absence.

Arthur Curry is settling quickly into his role as the King of Atlantis, with even newer roles as a husband and father. But his enemies are still lurking in the shadows and preparing for the perfect opportunity to strike, pitting the entire kingdom in danger of complete collapse. Aquaman and the Lost Kingdom is poised to close the DCEU, and the tie-in comic book special hints at an epic adventure to grace the silver screen by the end of 2023.

On sale now from DC Comics, Aquaman and the Lost Kingdom Special #1 is written by Tim Seeley, Joey Esposito, and Ethan Sacks, illustrated by Miguel Mendoça, Ray-Anthony Height, Scot Eaton, and Norm Rapmund, and colored by Andrew Dalhouse, Eren Angiolini, and Tony Aviña, and lettered by Wes Abbott, Josh Reed, and Carlos M. Mangual.

The Killer director David Fincher reveals why his Spider-Man movie didn't happen