Welcome to Night Vale isn’t a stranger to experimenting with the limitations of what a podcast is and how it can deliver its story. I suppose one shouldn’t expect anything less from a show where reality is a mere suggestion. One of the quirkier examples of this can be found in the September 2016 episode All Right, a cheeky missive that alternated sound delivery between the right and left headphones in ways that related directly to the plot — which involved something suitably creepy and doom-filled, as is Night Vale’s wont. And if you tuned in for the episode that dropped on Saturday, you would have encountered another technical experiment, though you might not have noticed it, especially if you only listened to the thing once.

Here’s the deal: Are You Sure?, the podcast’s 133th episode, features three different endings that are delivered to listeners at random. The team relied on dynamic insertion technology, the increasingly ubiquitous podcast tool that up to this point had mostly been used for ads, to build the experience. For the unfamiliar, dynamic insertion tech was developed to allow publishers to more easily swap out host-reads and ad spots with having to directly alter the podcast episode. Previously, ads were manually “baked into” podcast audio files, in that they were recorded as part of the performance material before being uploaded to the hosting result. As a result, it was significantly harder to apply changes to a show’s archives as you would have to re-splice new ads into older episodes and replace them on the hosting platform.

The technology has mostly been discussed in terms of its contributions to podcast advertising and monetization: it allows publishers to re-monetize their back catalogue, it enables them to quickly issue fixes to bungled ad spots, it opens up the possibility of better targeting. But with this experiment, the Night Vale crew illustrates another upside to the technology: it has distinct opportunities for creative execution.

“[Dynamic insertion] is a fascinating technology to me — that different people can download different versions of an episode,” said Joseph Fink, co-creator of Welcome to Night Vale, when we spoke over the phone about the experiment a few weeks ago. “It’s kind of baffling that nobody’s tried this before.”

The Night Vale crew, whose ad sales are handled by PRX and whose podcasts are hosted on PRX’s Dovetail platform, only created three endings because they were told that was the maximum number the platform could reliably handle at this point in time. Fink wrote one ending, while the other two were written by Jeffrey Cranor, his Night Vale co-creator, and writer Brie Williams. Their plan was to wait a few days after publishing the episode before telling anyone about the experiment, in hopes to create a situation where Night Vale fans would talk to each other about the story and organically discover that they didn’t exactly listen to the same thing. The uncertainty over which is the “true ending” will be preserved for now.

The deployment of different endings was designed to be purely random, with every subsequent download has a 66% chance of getting a different ending regardless of the listener’s context. But you can see how other editorial dynamic insertion frameworks can be designed and executed. For example, in theory, the tech allows for better targeting, and as such, if you could reliably identify the location of a listener, you could deliver editorial programming or journalistic information to that person specific to her city, town, or state. The possibilities that dynamic insertion technology offers news podcasts has long been an intellectual hobby horse of mine; I’ve long suspected that NPR’s Up First could make for a fascinating vessel for local podcasts in the way that Morning Edition’s broadcasts are reliable vessels for interspersed station spots.

Of course, more progress still needs to be made towards scale and stability. As mentioned, Night Vale could only reliably build for three endings based on Dovetail’s current architecture, and because the move is so new, there were general anxieties about whether the experience would be unsuccessful. Plus, there are all the orthogonal questions about the future of podcast delivery: how would the rise of smart speakers impact the machinations, utility, and design of podcast hosting platforms? How would a successful bid by Pandora on a Podcast Genome Project?

But those are questions for another day, another crossroad. For now, Fink tells me that fans responded to the episode very well. When successful, technical experiments like All Right and Are You Sure? are fun, engaging, and participatory; they capture the conspiratorial feel of Night Vale’s live shows. “There were listeners who thought the ending you got depended on the physical location the episode was downloaded in, and so they were traveling around their towns, trying to get them all,” he said. “We made our podcast into Pokemon Go.”