Acheron is the combination prison/military base in Beacon City where flunkees are sent.
"Sad Acheron of sorrow, black and deep." --John Milton
When General Lamson rebuilt Beacon City after the States War , he built it on top of a manmade hill. Inside the hill, he ordered the construction of a huge complex that would serve as both prison and military base. Flunkees or Markless criminals are sent to the prison, brainwashed, and integrated into the International Moderators of Peace (IMPS), who serve as Lamson's private army.
Within the hill that makes Beacon City, Acheron has nine levels. The first level is an artifical park, a setting intended to set flunkees at their ease before they are brainwashed and trained as IMPS. The sixth level contains brain-computer interface helmets for heresy--that is, for IMP backsliders. Level nine is intended for traitors, those Markless who committed crimes and were arrested by DOME. At the very bottom of the prison is a single solitary confinement cell.
There are only two entrances to Acheron. One is the front entrance, which is heavily guarded. The other is an entrance through the air ducts that open onto the Markless sublevel.
Revelation to the PublicEdit
"Our suspicions, our investigations...they can only take us so far. We're dealing with secrets so deep now, I'm not sure they belong to anyone anymore." --Daniel Peck
Initially, no one outside of certain government agencies knew of Acheron's existence. Flunkees were assumed to be dead, and speculation on where Markless criminals are sent remained speculation. Only gradually did the people of the Americas learn the real reason that Beacon is a city set on a hill.
Logan Langly always assumed that his sister Lily had died when she flunked her Marking. That was what the DOME agent who brought the news to his parents insinuated. But Daniel Peck informed Logan that Lily is alive, although only a Marker would know what happened to her. Logan Pledged in order to determine whether his Marker would back up Peck's story and tell him the truth about his sister. The Marker confided that Lily was taken to a place called Acheron in Beacon City. About a month later, Logan and Peck were reunited, and Logan gave Peck the specific details on what had happened to Lily. The word "Acheron" meant little to either of them at the time, but as they traveled eastward on the Unmarked River, both Logan and Peck heard a number of urban legends about the horrors of Acheron's prison.
Erin's computer hacking added the additional revelation that Acheron is a military complex as well as a prison. When the Dust entered Acheron to rescue Logan, they discovered that the urban legends were all true in that the brain-computer interfaces can simulate any number of horrible experiences, all aimed at brainwashing Acheron's unwilling inhabitants. Simulaneously, none of the legends were true, because no physical torture occurs within the prison.