As it turned out, Oliver Queen (Stephen Amell) did not become the next Ra's Al Ghul. He gave that title to Malcolm Merlyn (John Barrowman) at the end of last season. Then Oliver and Felicity (Emily Bett Rickards) drove off into the sunset.

While that may be the perfect ending for the characters, the blissfulness will pass. After all, it is "Arrow" and superheroes just can't get that kind of happy ever after so soon.

Here are some of the biggest spoilers to watch out for:

1) Felicity will meet her own nemesis, as the series will introduce a recurring character who will have techie skills that can match Ms. Smoak's. While there is no news where he comes from, TV Line noted that fans suggested he will be Felicity's H.I.V.E. counterpart.

2) Barrowan will definitely be back for the fourth season. He told the audience at the Las Vegas Comic Con that he will start filming in July, although he did not divulge details about what's going to happen to his character. He did insist though, that "you're going to love what's going to happen across the DC world."

3) Caity Lotz (Sara Lance) will definitely be part of "Legends of Tomorrow" and will be revived via the Lazarus Pit. However, there is no certainty whether she will be revived on "Arrow" or in the spinoff, come 2016. One thing is for sure, though: Sara Lance's reappearance will mean that she will take the identity of the White Canary, as reported by Cinema Blend.

4) Malcolm Merlyn will not be the Arrow's adversary in the new season. According to iDigital Times, Oliver Queen and the gang will be fighting new villains: Damien Darhk and H.I.V.E.

Previously mentioned last season, the identity of Darhk will finally be revealed as he will try to seize control over the League of Assassins.

5) While fans definitely missed the Arrow, E! noted that the actor said in an interview that his character already gave up his suit, and with everyone knowing his real identity, it will be somewhat counterproductive to return.

He did hint a little about possible flashbacks but that's about it.

"I know a little bit about the flashbacks; actually, I know the whole flashback story. But in terms of present day, I don't know. Roy sacrificed himself (he outed himself as the Arrow), so if I were to recreate the suit and go out, it would undo all of the sacrifice that he made. So the Arrow persona - for better or for worse - it can't exist anymore," Amell told TVLine.

"Arrow" will return for its fourth season on October 7, at 8 p.m. on The CW.

No official trailer has been released yet, but check out this fan-made trailer, it will leave you wanting more: