By Natalie Abrams
January 26, 2017 at 04:13 PM EST
Diyah Pera /The CW

The Invasion isn’t the only time we’ll be seeing the worlds of Arrow, The Flash, and DC’s Legends of Tomorrow collide.

“Next week’s episode of Arrow features, I will say, the fastest crossover with Flash we’ve ever had,” Arrow and Legends executive producer Marc Guggenheim told EW on our SiriusXM radio show Superhero Insider.

But wait, there’s more! “We, just yesterday, made an offer to an actor to reprise their role from one of the other shows in the season finale of Legends,” Guggenheim teased. “Oh, and in the penultimate episode we’re gonna have — I can’t be specific about this, but it’s one of the most fun things I think we’ve ever done on the show — a character from one of the other shows on Legends in a way that you’ve never seen before, you may never see again, but will, I think, just send fans into squeals of joy.”

In the interview, which you can listen to in full below, Guggenheim also teases a possible Black Siren return, hints at the new potential Black Canary’s abilities, and drops even more spoilers when discussing whether Legends‘ move to Tuesdays behind The Flash has played a role in upcoming storytelling.

“We’re going to be seeing the Black Flash on Legends,” Guggenheim says, reminding fans that Thawne is a member of the Legion of Doom. “Lily Stein, who was introduced in Flash 308, makes an appearance next week. So there’s a fair amount of Flash-ness going on in Legends. I wish I could say that we were so smart to take advantage of the new timeslot and do that, but we weren’t that smart. We just had already sort of been doing that organically anyway when we found out about the new timeslot. I will say this: There’s a love scene in episode 11 and we were in the editing room on it — it’s a love scene, it gets a little steamy — and I was joking, ‘Let’s take that 9 p.m. timeslot out for a spin.'”

[soundcloud url="" params="auto_play=false&hide_related=false&visual=false&show_comments=true&show_user=true&show_reposts=false&color=ff5500" width="100%" height="166" iframe="true" /]

DC’s Legends of Tomorrow airs Tuesdays at 9 p.m. ET, while Arrow airs Wednesdays at 8 p.m. ET on The CW. Tune in to SiriusXM’s Ch. 105 on Thursdays at 11 a.m. PT/2 p.m. ET for more on The CW’s super series on Superhero Insider, hosted by Kyle Anderson and this reporter.