Be warned, if you didn't watch last night's season finale of The Flash, there will be MAJOR SPOILERS discussed below, so read on at your own risk. Last night's "Fast Enough" brought the season to a close in shocking fashion, with one member of Team Flash making the ultimate sacrifice to prevent Reverse Flash (Tom Cavanagh) from causing any more damage. Now that the countdown to The Flash Season 2 has officially begun, executive producer Andrew Kreisberg shed some light on how the season finale will impact the show moving forward. Here's what he had to say about the second season.

"We're mapping out the (second) season. The circumstances in which we come back will hopefully be surprising and entertaining. There are a bunch of questions that were left unresolved at the end of the season and they'll be resolved in the premiere. But how that happens won't quite be the way people expect. Hopefully the unexpected is what people have come to expect from us."

In last night's season finale, Barry (Grant Gustin) decided against using the time machine to save his mother's life, and instead went back to the present, where Harrison Wells/Eobard Thawne (Tom Cavanagh) was determined to kill Barry and everyone he cares about. One of the most shocking moments came when Detective Eddie Thawne (Rick Cosnett) decided to take his own life, causing his descendant Eobard Thawne to essentially be erased from the timeline. However, despite his heroic sacrifice, fans haven't seen the last of Rick Cosnett's Eddie Thawne, although he will no longer be a series regular on The Flash moving forward.

"It's hard. It's a terrible decision to have to make. We've been faced with that before, certainly when we made the decision with Colin Donnell on Arrow and Caity Lotz. As with both of those actors and characters, they lived to come back another day. While Rick won't be a regular, Flash is the kind of show between hardcore sci-fi and time travel that I wouldn't be surprised if this isn't the last we've seen of Eddie Thawne."

He also added that, despite being erased from the timeline, Tom Cavanagh will continue to be a series regular on the series.

"Tom Cavanagh will continue to be a regular on Flash is all I am prepared to say. On Flash, you've never seen the last of anybody, no matter what happens to them."

We reported earlier this week that the second season will deal with the separate universes in the multiverse, which is likely how the show will be able to bring back Eobard and Eddie Thawne. The finale ended with a massive black hole beginning to engulf Central City, with Barry leaping inside of it to save the City, before the show cut to black. Andrew Kreisberg teased that not everything will be the same when Barry returns to his hometown.

"When you open a singularity above a city, you should be worried about anything and everything that happens. Part of the fun of The Flash is when you have people dabbling in sci-fi physics, they're significantly altering the world. We established in the finale that the entire series of The Flash is, in itself, an alternate timeline that's been skewed from the real one. Wells setting off the accelerator created all the metahumans, and the results of the singularity will also have long-term effects."

When Barry went into the future by using the Speed Force, there were a number of Easter Eggs present, such as a glimpse of Caitlin Snow (Danielle Panabaker) transformed into the villainous Killer Frost, Barry seeing a statue of himself, and the helmet of the original Flash, Jay Garrick, which you can see in the photos from the finale below. Are you excited for the second season of CW's The Flash? Chime in with your thoughts below, and CLICK HERE for Andrew Kreisberg's full interview.

<strong><em>The Flash</em></strong> Season 1 Finale Photo 1

<strong><em>The Flash</em></strong> Season 1 Finale Photo 2

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<strong><em>The Flash</em></strong> Season 1 Finale Photo 3