A new fan theory suggests that the father of Jonathan and Will Byers will make a return in Stranger Things season 4. Lonnie Byers was played by Ross Partridge and appeared in a total of four episodes during season 1 of the Netflix series. Here's what a reunion could mean for the Byers family and how it makes sense with the direction of the plot.
Lonnie and Joyce were divorced prior to the events of Stranger Things season 1. He was a deadbeat father who made no effort to carry on a relationship with his sons after moving out of Hawkins. When Will went missing, Joyce knew he wouldn't go to Lonnie. That didn't stop Jonathan from checking with his father, but Lonnie wasn't even concerned that his young son had disappeared. When the body was found in the quarry, Lonnie reappeared but it wasn't for the funeral like people first thought. Instead, Lonnie was interested in making money from the quarry where Will drowned.
After discovering Lonnie's true motives, Joyce chased him away and he hasn't been seen in Stranger Things since. It's unclear if he ever learned that his son was alive. That may soon change according to a recent theory (via Reddit). To celebrate the start of season 4, Netflix released a video of the cast coming together for a table read. In the background of the video, there's a man who looks like Partridge, leading viewers to believe that Lonnie is set to return in the upcoming season. Though no confirmation has been made regarding the character's presence in the new season, it wouldn't be surprising.
Why It Makes Sense For Lonnie Byers To Return In Season 4
By the end of season 3, Joyce decided to take her sons and Eleven out of Hawkins. They packed their belongings and set out for a new residence, but their destination was never revealed. It had been stated that Lonnie lived in Indianapolis, so it would be unlikely Joyce would take the kids to that area. With the Byers out of their house in Hawkins, Lonnie might return to town and reclaim his old house now that it's up for sale. There could also be a darker reason for his return.
Will had a history with Hawkins Lab before it was shut down, and it was made clear that the Russians infiltrated the building. If they found out about Will and how he was infected by the Mind Flayer, the Russians might want him as a test subject. If that's the case, they could go to the boy's father, who also happens to be a drunk that would do anything for money. There's speculation that Joyce and Murray will travel to Kamchatka to rescue Hopper, which would leave the kids without an adult looking out for them. Lonnie could find out their new location and track down Will to deliver him to the Russians. However, Will is no longer the weak little boy that Lonnie remembers. With Eleven by his side and Jonathan in the mix, they could finally get real payback on one of Stranger Things' earliest antagonists.