Arrow's Marc Guggenheim told EW that the Season 6 finale is "a real game changer."

Arrow Executive Producer Marc Guggenheim made a visit to Entertainment Weekly’s Superhero Insider this week where he talked about this week’s excellent Legends of Tomorrow season finale as well as talk about next year’s (!!) crossover. For Arrow fans, though, the highlight was some teasing about what we can expect from the Season 6 finale which Guggenheim describes as a “game changer.”

“I’ve been saying it’s an unconventional kind of finale. It still feels very much like a season finale. When I first started talking about it we hadn’t written the darn thing yet, but now we’ve written it, and we’re in prep on it, and on Monday we start shooting. And it’s a real game changer,” the producer said.

“The show fundamentally changes in the finale and I think you’ll see there’s stuff that we were seeding back in the season premiere that finally comes to fruition here in the season finale, so you’ll see that there was a very specific plan to the entire season,” Guggenheim continued. “We always knew this is where we were headed to. Hopefully in subtle ways, we have been teasing this all along without you realizing it. My hope is that people are surprised, but also look back and are like ‘oh, that was kind of the only way that they could have ended the season’.”

Stephen Amell recently told fans that whatever big events happen in the finale cannot be undone, and Guggenheim confirmed this information.

“That is, yes, that is exactly true. In fact, it’s the kind of game-changer that we’re not going to buy back at any point. It fundamentally changes the show,” Guggenheim said.

Guesses? Leave them in the comments section below! You can hear EW’s Superhero Insider here.