WARNING: The following article contains spoilers for HBO's The Outsider.
HBO's The Outsider has kept the veil of mystery up regarding the title character, a shape-shifting ghoul that's now taken its child murder spree to Cherokee City, Georgia. With fall guys such as Terry Maitland (Jason Bateman) now coming to light with clues being dug up by genius private investigator Holly (Cynthia Erivo), the team detective Ralph Anderson (Ben Mendelsohn) has is simply trying to understand what this being is and how it selects its patterns.
However, as Holly digs deeper to find out what the creature is, she comes across a concept from Hispanic culture called the Grief Eater, which perfectly describes this monster they have no idea how to catch.
Holly's digging up of evidence has taken her to a child killer who committed suicide in jail, Heath (Martin Bats Bradford), and she realizes everyone related to him died too. His mom, the latest death, killed herself in a car crash after failing to accept how Heath was jailed despite being with his family when his doppelgänger killed the kids. He decided suicide was better than abuse in prison and slit his own throat, opting to not see the conviction out. A dogged Holly eventually trails his romantic past back to another child murderer: Maria Caneles (Diany Rodriguez).
Riker and Holly are immediately taken aback as she's the only murderer who's alive, which could make her Patient Zero. What's interesting is with the other killers, all their relatives died, but Terry's family is still alive so Holly knows it's just a matter of time. When she and Maria speak, Holly clues into the Outsider being a Boogeyman Maria is afraid of, one that impersonated the latter and slept with Heath before taking his form. It'd then have an encounter imitating Heath at a retirement home, which led to it copying Terry.
But getting proof of this theory is a hell of a thing because while Holly has evidence other killers like Terry were in two places at once, explaining the doppelgänger is difficult as there's no conclusive evidence. Luckily, an inmate's mom overhears Holly discussing Maria's predicament and has a private session at her home where she speaks of "El Coco." It's a monster that feeds off the angst of not just its victims, but others around it. It's called the 'Grief Eater' in English and it's why the child killers lose all their family members.
It also sucks the life out of the children's families, evidenced by the Peterson family whose kid Terry was accused of killing. The hooded-man suspected to be is shape-shifter was present when the accused was killed by the Peterson's eldest boy, as well as when the mom died due to heart failure. And it's why the being is sticking around to drain the Maitlands after Terry's death. It completes the full-circle picture by absorbing the grief of everyone involved, strengthening itself to feed later on.
With the Peterson dad in I.C.U. and the ghoul making threats to Terry's daughter, its mission isn't done yet. The malevolent spirit wants to finish eating their grief and will wear whatever skin it has to in order to do so, including Jack, another Cherokee cop. The woman, a spiritual advisor, shows Holly pictures of art throughout history, including the Saturn Devouring His Son painting by Francisco Goya, and makes it clear this being is demonic and wants to consume the pain of all mankind.
Any doubts Holly has are erased with Maria's tragic story of how the grandad of the kid she went to jail for killing actually drove to a bar and shot her father and brother dead in cold blood. This is yet another example of the 'killer' suffering loss and so, Holly begins researching this kind of creature in other cultures because it seems to be what's plaguing the Peterson case. Something is devouring grief on both sides of the equation but she may not have an answer on how to stop this Boogeyman as he's turning out to be much more than a myth. Thanks to this conversation, though, she's now dead-set on educating Ralph's crew and letting them know they're dealing with a force way beyond their comprehension and they're going to have to go into the mystical territory to get justice for all.
Starring Ben Mendelsohn, Cynthia Erivo, Bill Camp, Mare Winningham, Julianne Nicholson, Paddy Considine, Jeremy Bobb, Yul Vazquez, Marc Menchaca and Jason Bateman, The Outsider airs on HBO on Sundays at 9 p.m. ET/PT.