"Acheron: Part I" is the first episode of the eleventh season of AMC's The Walking Dead. It is the one-hundred and fifty-fourth episode of the series overall. It premiered on August 22, 2021. It was written by Angela Kang & Jim Barnes and directed by Kevin Dowling.
Daryl leads a mission team to scavenge the military base he discovered. Maggie tells her story, prompting a new mission for survival that only Negan can lead. Eugene and his group go through assessment by the Commonwealth's paramilitary police.
Maggie leads a small group into a helicopter hangar. They enter a room filled with walkers immobile on the ground. They step quietly around the walkers. Magna breaks the lock on a door and the group proceeds down a hallway. They find a crate full of MREs, and stuff the supplies into their backpacks.
Maggie, Carol, and Rosita load the backpacks onto a pully system. Daryl and Alden hoist the packs up. A pulley snaps. Daryl grabs the backpack before it can fall on top of the walkers, but he cuts himself on the arm, and a drop of his blood lands on a walker. The walker stirs, rousing all the other walkers in the room. Maggie's group starts slaying the walkers. Daryl and Alden hoist the crew up to safety one by one.
The group returns to Alexandria. Daryl hugs Judith and R.J. Hershel runs up to Maggie with Cole, Duncan, and Agatha, members of Maggie's old community who have made their way to Alexandria in search of Maggie. Nearby, Gabriel breaks up a fight between people arguing over food rations.
Gabriel presides over an emergency meeting and announces that Alexandria only has enough food to last a week. Maggie proposes they replenish their supplies by taking back her old community, Meridian, which was seized from them by a group that slaughtered most of her people. Daryl and Gabriel volunteer to join her.
Maggie leads a team through Washington, D.C., en route to Meridian. Caught in a thunderstorm, they decide to take shelter in a subway station.
Maggie's team descends underground. Daryl suggests they travel via the subway tunnels. Negan vehemently disagrees, but Maggie orders him to tell them the quickest subway route to Meridian, since he's the most familiar with D.C. They jump onto the tracks.
The group walks down a subway tunnel. They hear pipes groaning from the storm winds. Negan points to a watermark on the wall, indicating that the tunnels regularly flood. He suggests they turn around, but Daryl shoots down his idea.
Ezekiel interrupts his interrogation, and correctly guesses that a trooper who's quietly been watching is actually the person in charge. He coughs uncontrollably. The trooper, Mercer, passes him a glass of water.
Ezekiel's group eats together in a detention center. Princess, Yumiko, and Ezekiel agree that they must try and escape, but Eugene argues that the Commonwealth might be able to help Alexandria. Princess asks some fellow prisoners how long they've been there. One of the prisoners says he can't remember on account of the "reprocessing," then trails off. Troopers haul away a prisoner to take him in for reprocessing. Eugene changes his mind and agrees they need to escape.
In the subway tunnel, Maggie's group encounters a pile of dead bodies, each wrapped in plastic. Daryl removes the plastic from one body and kills the walker when it snaps at him. They observe the walker made no noise because its throat had been slashed. Maggie instructs the group to kill all the walkers so that they can proceed.
Maggie's group stabs each walker dead. A huge walker silently attacks Gage. Negan kills the walker and refuses to go further, calling Maggie's plan a death march. Gage and Roy agree with Negan, but Maggie insists Negan needs to stay with them to guide them through D.C. Negan guesses that Maggie just brought him along to send him to his death. Maggie admits that she constantly thinks about killing Negan, and isn't sure how long her self-restraint will last.
Eugene's group discusses an escape plan. Princess watches their guards with amusement, and describes details about the troopers that no one else has noticed. She reveals that two of the troopers routinely disappear for half an hour to have sex. They hatch a plan to escape during this window of time.
Yumiko and Eugene wear trooper uniforms and escort Princess and Ezekiel down a hallway. A trooper demands to know where they're going. Yumiko says they're taking the prisoners to reprocessing. The trooper lets them go.
They escape the building and pass by a wall papered with photos of prisoners. Princess recognizes Yumiko in one of the photos. Yumiko sees that the photo is accompanied by a note from her brother, asking if anyone has seen Yumiko. She realizes her brother is at the compound and decides she must stay and find him.
Maggie's group realizes that Gage and Roy secretly fled and took all of their supplies. A herd of walkers appears further down the tunnel. They start killing the walkers and look for an escape route. Daryl runs after Dog as the rest of the group climbs a ladder to safety. Maggie is the last one to ascend the ladder. A walker grabs her leg. She cries out to Negan for help, but he abandons her. She loses her grip and falls.
- Antony Azor as R.J. Grimes
- Kien Michael Spiller as Hershel Rhee
- Carrie Genzel as Clark
- Marcus Lewis as Duncan
- Matthew Cornwell as Evans
- Mariana Novak as Female Trooper
- Brandon O'Dell as Refugee Man
- Mala Bhattacharya as Refugee Woman
- Joshua Haire as Squirrelly Man
- Seven as Dog
- Jason Fernandes as Livits
- Terrance James as Zell
- Anthony Porrey as Alexandria Resident
- Michelle Morano as Alexandria Resident
- Marcus Tyler Estes as Alexandria Resident
- Tonia Wienecke as Alexandria Resident
- Alex Barnes as Alexandria Resident
- Ian Kincaid as Alexandria Resident
- Kevin Cheek as Alexandria Resident
- Matt Foster as Alexandria Resident
- Melanie Dale as Alexandria Resident
- Sonya May as Alexandria Resident
- Unknown as Garcia
- Unknown as Sorsensen
- Numerous unnamed U.S. Military soldiers (Alive, Confirmed Fate; Zombified)
- First appearance of Frost.
- First appearance of Duncan.
- First appearance of Agatha.
- First appearance of Garcia.
- First appearance of Clark.
- First appearance of Evans.
- First appearance of Michael Mercer.
- First appearance of Sorsensen.
- First appearance of Zell.
- The title of the episode, "Acheron", refers to one of the rivers of the underworld within Greek mythology, which was known as the "river of woe".
- This episode was made available for streaming to subscribers of AMC Premiere on August 15, 2021.
- As of this episode, Cooper Andrews (Jerry) and Callan McAuliffe (Alden) have been added to the opening credits.
- Eleanor Matsuura (Yumiko Okumura), Nadia Hilker (Magna), Cailey Fleming (Judith Grimes), Cassady McClincy (Lydia), and Lauren Ridloff (Connie) are still listed under "Also Starring" despite being regulars in the previous seasons.
- This is the first episode featuring Paola Lázaro (Juanita Sanchez) and Michael James Shaw (Michael Mercer) as series regulars. They are listed under "Also Starring".
- Jackson Pace (Gage) and Okea Eme-Akwari (Elijah) are upgraded from "Co-Stars" to "Also Starring" in this episode.
- Lydia is seen using her staff for the first time since she lost it and it was recovered by Carol in "Walk With Us". In addition, the staff is seen for the first time since Carol returned to Alexandria with it in "Look at the Flowers".
- This episode starts hours after the end of "Here's Negan", the group going on the supply run that Carol had mentioned to Negan at the end of that episode.
- In the subway, the group find a walker unable to make any sound because of its slashed throat. This is in contrast to what has been observed in previous seasons, in which on several occasions walkers have been observed making their typical sound even after a complete beheading.
- Almost every photo on the Commonwealth's "Wall of the Lost" came from the show's crew members.
- The original plot summary for the episode was as follows: Returning to Alexandria from a critical food mission, the group realizes it isn't enough. Maggie proposes a new plan, potentially a suicide mission. What choice do they have? They must find more food for all their people in order to survive and efficiently rebuild Alexandria. If they don't, Alexandria falls, taking them down with it. Once on the road, a violent storm erupts forcing them underground into a subway tunnel. As nerves fray and suspicions increase, chaos ensues. The terror is relentless as our people get a glimpse of what Maggie and her group endured prior to returning to Alexandria. Meanwhile, those captured by the stranger soldiers are relocated to another undisclosed location.
- Eugene and his group being interrogated is adapted from Issue 175.
- Yumiko seeing her picture on the Wall of the Lost and finding out her brother is alive in the Commonwealth is adapted from a similar scene in Issue 175, where Michonne finds out her daughter Elodie is alive instead.
- Alexandria is revealed to have been severely damaged by the Whisperers' attack with the residents being left with broken tools, several burned houses and other buildings, almost no food even after the Fort Connors supply run and a damaged defensive wall. In addition, Daryl reveals that their hunting grounds are spent because the Whisperers' horde scared all of the animals away and they don't have enough time to find new territory.