Screenshot: The CW

Legends of Tomorrow is going to have another crossover episode, but not, as you might expect, with anything in the Arrowverse. Instead, SYFY Wire reports, the CW series is colliding with Supernatural, which is currently on its fifteenth and final season.

Of course, this being The CW, this isn’t just any old crossover. As the publication explains, Supernatural is a TV show in the universe of Legends of Tomorrow, which means the characters will be interacting with the filming crew of Supernatural, not the Winchester brothers themselves.

“Sam and Dean did not make the final cut, unfortunately,” Legends of Tomorrow showrunner Phil Klemmer told Entertainment Weekly. “Or rather they were busy working on their own show.”

So how does that work? Does this mean The CW is also still a channel in the universe of Legends of Tomorrow, just with slightly different programming?What replaces Legends of Tomorrow in Legends of Tomorrow? Or is is Legends of Tomorrow still a show in Legends of Tomorrow? Do the characters sit around for a weekly recap of their adventures and transgressions, dreading what they’ll see onscreen?

This is Legends of Tomorrow we’re talking about, so all of that would be easily plausible. Looks like we won’t be getting any answers until the episode (“Zari, Not Zari”) airs on March 24, but EW did include some photographic sneak-peeks, which show Constantine (Matt Ryan), Charlie (Maisie Richardson-Sellers), and Sara (Caity Lotz) gazing with consternation at what appears to be a dead body in the trunk of Dean Winchester’s 1967 Chevrolet Impala named Baby. (Another fun detail is the Supernatural Filming in Progress sign in Sara’s hand).

“We wanted to do a spooky, Predator-style skulk-around-the-woods episode and at the 11th hour decided to have the Legends intersect with the crew of Supernatural,” Klemmer told EW, adding that the car is not the one from Supernatural, but rather a super-fan’s replica.

For more about the episode, including pictures from the set, check out the full interview at Entertainment Weekly.