Most would agree that Stranger Things managed to recapture old magic in Season 2, though at least one outlying episode divided fans. Now, even the Duffer brothers admit that Eleven’s excellent adventure was “kind of a crazy thing to do,” but one they needed to make the finale work.

You’re warned of full spoilers for the second season of Stranger Things from here on out, but fans were undoubtedly puzzled by the seventh episode, which left Hawkins behind to explore Eleven on the road with fellow experiment Kali (Linnea Berthelsen) and her motley crew of avengers. There’s nothing wrong with expanding the show’s horizons, but “The Lost Sister” did interrupt a crucial point of momentum back in Hawkins, and largely served to send Eleven back home anyway.

So, why the risk? Why not just splice Eleven’s journey across multiple episodes? As Matt Duffer told Entertainment Weekly, he and Ross needed to prove to themselves that Eleven’s arc mattered:

Whether it works for people or not, it allows us to experiment a little bit. It’s important for Ross and I to try stuff and not feel like we’re doing the same thing over and over again. It’s almost like doing a whole little other pilot episode in the middle of your season, which is kind of a crazy thing to do. But it was really fun to write and cast and work on … Our test of the episode was we tried to pull it out of the show just to make sure that we needed it because I didn’t want it in there as filler — even though some critics are accusing us of doing that. But Eleven’s journey kind of fell apart, like the ending didn’t work, without it. So I was like, whether this works or not, we need this building block in here or the whole show is going to collapse. It’s not going to end well. The Mind Flayer is going to take over Hawkins.

Ross likened the episode to Luke Skywalker needing to spend time on his own in The Empire Strikes Back, before returning to save the day. If nothing else, the experiment at least introduced us to Kali and the potential for other numbered characters to appear in future seasons, as well to establish that Dr. Brenner (Matthew Modine) is still out there, lurking in the shadows.

We’ll see if time bolsters any appreciation for “The Lost Sister,” but should Stranger Things have left an hour on the cutting room floor? Stay tuned for more on Season 2 and beyond in the coming days.

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