What Did Will Byers Cough Up In 'Stranger Things' Season 1? Here's What We Know About That Gross Ending

Last year's Netflix hit Stranger Things ended on a mostly positive note. Mike Wheeler and his gang defeated the dreaded Demogorgon, mostly thanks to the telekinetic girl Eleven, with a side assist from Mike's sister Nancy and her crew. Meanwhile, Chief Hopper and Joyce Byers went into the Upside Down and brought back Joyce's missing son, Will. Everything was back to normal. Until, that is, Will popped off to the bathroom at dinnertime, and started spitting up in the sink. What did Will Byers cough up at the end of Stranger Things Season 1? And what does that portend for his fate in Season 2?

Heading into the new season, we already know from the new trailers that the Upside Down hasn't finished with Hawkins, Indiana, and neither has Eleven. The Demogorgon may have been defeated, but new monsters have been added to the brand new 1983 edition of the Dungeons & Dragons monster manual, including the dreaded Thessalhydra, which we saw the boys defeat in their latest campaign.

With many thinking the Thessalhydra is the new monster of the series, that could be bad news for Will once again. Especially because it might be related to what he's spitting up in the sink.

So, what are those things? Most thought them to be slugs when the show first landed, or perhaps maggots of some sort. A few had the theory they could be larvae, but for what, we couldn't be sure. Any way you looked at it, it was proof that Will Byers was not nearly as okay from his ordeal as he was pretending.

Let us consider, though, where Will was found prior to being rescued. Joyce and Hopper were searching through the doom and gloom of the Upside Down when they came upon something that was sort of a cross between the Queen Endoparasitoid Extraterrestrial's nest from Alien and Shelob's spider webs from Lord of the Rings.

Caught inside the gooey webbing are children, all of whom seem to be around Will's age. (Some fans have theorized they could be numbers 1 through 10.) Some are mere skeletons, some are dead and decomposing. Will is there among them, still alive, with some sort of umbilical-like cord thrust down his throat.

At the time, the image is supposed to recall that of a child being connected to oxygen in the hospital, triggering more memories for Hopper of his daughter, who died of cancer. This, in turn, drives him to pull the cord from inside Will and free him from the Upside Down.

But for those of us who are students of 1980s movies, it's also not so unlike what happened to John Hurt in the first Alien movie when the Facehugger grabbed a hold of him and impregnated him with the tiny alien that was then born via his chest. A scene so remarkable, it even has one of the all time great parodies.

These references would all be things the Duffer Brothers were thinking about. But Will hasn't burst anything out of his chest (at least, not in the trailers so far). With actor Noah Schnapp (who plays Byers) upped to series regular, we assume he'll survive all nine episodes just fine.

But that doesn't mean the slugs he's spitting up are harmless. If one checks the 1983 Monster Manual II, the description of the Thessalhydra's breeding habits includes that it "infects hosts with larvae."

Suddenly, we have a very good idea what those other children who died down there in the dark might have been used for. Moreover, if this really is what is going on, Will's quiet barf up of tummy slugs in the sink means he's been infecting the town's entire sewage system with baby Thessalhydras.

Someone ready the fireballs and hope we roll a 13 or higher. Stranger Things Season 2 drops all nine episodes on Netflix on Friday, Oct. 27, 2017.