Some big changes are about to occur in Oliver Queen's world, but you don't need to watch "Arrow" to know that. All you need is to watch the new trailer for "The Flash."

Following last night's episode of the super-fast superhero show, The CW unleashed a trailer teasing the final few episodes of "The Flash" season one. Among the many teases and Easter eggs contained in the super-cut, Oliver Queen stands out for one especially terrifying reason. Watch the trailer below to see for yourself, but be warned, SPOILERS for "Arrow" are ahead:

Did you see Oliver's blink-and-you'll-miss-it cameo starting around the 45-second mark? There's glimpses of Starling City's emerald archer over the next five seconds, and if you look closely, you'll see Ollie sporting a brand new costume — brand new for him, anyway.

He's wearing what appears to be a riff, if not exact replica, of the Dark Archer uniform — aka, Malcolm Merlyn's bow-wielding outfit. What that means exactly is up for interpretation. Are Oliver and Malcolm becoming such good pals that they're raiding each other's closets? Or are they becoming such great foes that Oliver is going to kill Malcolm and wear his outfit as a sign of dominance? Or, is Oliver Queen actually about to become the new Ra's al Ghul and leader of the League of Assassins?

However you slice it, the fact that we see Oliver wearing Dark Archer attire in the new "Flash" trailer should set off some major bells for what's still to come this season on "Arrow." Hit us up with your theories on where you think Oliver's aiming next.

Beyond the "Arrow" of it all, the "Flash" trailer reveals a lot of big details about what's coming up in the last stretch of episodes this year, from the debut of Ray Palmer's Atom in Central City, to the big bad arrival of Gorilla Grodd. (He looks amazing, by the way!) That's not even mentioning all the glimpses at Not Harrison Wells and his haunting Reverse Flash secret. Sadly for Cisco fans, it looks like a certain confrontation is still on the way — but hopefully, this time, Barry Allen's time-traveling abilities will be able to stop this from happening:

If nothing else, the trailer makes it clear that "The Flash" is going to close out its first season the way it's been running this entire time — full-speed, and full-awesome.