The first season of "The Flash" wrapped just last night on The CW, but it's the nature of fans to wonder what's next as soon as possible -- and when a debut season ends like "The Flash" did, clearly the folks behind the series are inviting a high degree of speculation.

FLASH FORWARD: Five Threats We Want to See on "The Flash" Season 2

Luckily, there's no need to rely solely on wild guesses -- the show's executive producers, namely Andrew Kreisberg, have already revealed some rather solid hints on what to expect for "Flash" season 2, even with it four or more months away, not to mention the teases in the season finale itself. Here's a look at what "Flash" fans can expect for sure in the second season of the DC Comics-based hit.

• Birth of the Multiverse: Prior to last night's finale, Grant Gustin revealed that season two of the show will feature a Multiverse of sorts as Barry travels to parallel Earths -- specifically Earth-One and Earth-Two.

  

  

  

  

  

  

  

  • Jay Garrick?: Last week, a set photo from "Flash" emerged that depicted both a Time Sphere and what appeared to be original Flash Jay Garrick's helmet. We saw the event depicted in the set photo come to pass in last night's episode when Garrick's Flash helmet popped out of the wormhole. When you toss in the fact that Gustin has mentioned a visit to Earth-Two, Garrick's traditional home reality, and Daniele Panabaker namedropped the classic DC hero during a recent Reddit AMA, it seems likely that we'll get to meet the first Flash next season.
  • Even more speedsters: Jay Garrick's helmet is just the latest hint at the breadth of the Speed Force. "The Flash" showrunners have been talking about Wally West since before the pilot even aired, and a post-finale chat with THR indicates even more are on the way. "We are going to introduce a few more speedsters next year and a bunch more villains," Kreisberg said. "How they and those villains come about is part of the surprise of season two."
  • Tom Cavanagh ain't gone: While it looked like Harrison Wells/Eobard Thawne met the most final end imaginable in the season one finale (he was wiped out of existence!), Kreisberg said in a few post-episode interviews that Cavanagh will still be a series regular in season two. He also mentioned that he hopes to work with Matt Letscher, the man who played Eobard's true form, again. Considering that season two might include a trip through the Multiverse, it's possible that Cavanagh could play an unaltered -- and therefore not evil -- Harrison Wells next season.
  • Rick Cosnett's probably not gone either: While Cosnett's Eddie Thawne won't be a regular next season following his death by a self-inflicted gunshot wound, Kreisberg did say that death on shows like "Arrow" and "Flash" aren't always permanent. It's possible that Cosnett could appear again in alternate realities or flashbacks, or they could even resurrect him like they're about to do with Caity Lotz's Sara Lance. Still, unlike Cavanagh, Cosnett will not be a series regular next season.
  • More "Arrow" crossovers: It's no secret that the first full-on crossover between the two shows went over big, with fans and network execs. So while it was probably a no-brainier to make it an annual tradition, it was nice to hear it re-confirmed recently that yes, "Arrow" and "The Flash" will continue to populate each others' adventures with more than just the occasional inter-city cameo.
  • Robbie Amell's return: As one-half of the current Firestorm incarnation, Amell's absence from every teaser for "DC's Legends of Tomorrow" has kept fans guessing as to what will happen when the hero sets up shop outside of Central City. And while the star's lips remained sealed as far as what the spinoff holds for his and Victor Garber's shared character, Amell told CBR News earlier this week, "I can tell you that I will be in Season 2 of 'The Flash.'"
  • "Legends" cast pulling "triple duty": With three shows on the air, it's been revealed that certain cast members will rack up appearances on "Flash," "Arrow" and "Legends of Tomorrow" next season. Gustin specifically mentioned that Captain Cold (Wentworth Miller) and Heatwave (Dominic Purcell) would be two of the characters going for the CW/DC hat trick next year. Additionally, with Robbie Amell confirming his "Flash" return, it's a good bet Garber's Prof. Stein will be appearing on at least two of The CW's series.
  • Cisco and Caitlin -- metahumans?: In one of last night's shocking reveals, Eobard Thawne hypothesized that the particle accelerator accident that created the metahumans also had an effect on Cisco, which is what has allowed him to see the "vibrations" from the timeline that Barry Allen erased a few episodes prior. Additionally, the Flash raced past an image of Caitlin Snow in her Killer Frost persona from the comics while traveling through the wormole. Panabaker spoke about becoming Killer Frost in a recent Reddit AMA. In hindsight, it's possible all of her comments were referring to the brief shot in the season finale, but there's still a chance we'll see more of Killer Frost next season.

• Brett White and Stephen Gerding contributed to this article.