Last night’s Flash outing finally introduced us to Season 3's big bad “Savitar,” a hulking self-described “God of Speed” that last had Barry pinned against the wall. His lightning movements made the CG character difficult to see at first, but one small detail raises an interesting question, and might just upend Cisco’s prophesied “Vibe” about Caitlin becoming an evil “Killer Frost.”

Full spoilers for Flash Season 3 from here on out, but last night’s “Shade” pulled double-duty laying some of Season 3's cards on the table; not only outing Caitlin to the team as a chilly metahuman, but also introducing Dr. Alchemy’s master, Savitar. The former took place after Cisco vibed (by her own request) visions of a fully-costumed Killer Frost and Vibe tossing blasts at one another in close-quarters, seemingly confirming Caitlin as an imminent danger to the team.

The CW

Much later in the hour, Barry, Joe and Wally used Alchemy’s siren song in an attempt to trap the villain, only for the operation to turn horribly awry. The room began to shake, as a whisking white light only Barry could see effortlessly took down the police officers, before turning to Barry himself.

The CW

At first, it seemed that “Savitar” was capable of moving at speeds that only Barry could even glimpse, but one quick shot from the encounter below tells a different tale. Did you catch it?

The CW

That isn’t the first time we’ve seen The Flash avoid showing Savitar directly, as we at least saw an arm in Edward Clariss’ demise (“Paradox”), while security footage of the event (“Magenta”) showed similar white flashes, but the above shot marks the first demonstrable instance of Savitar being completely stationary, yet entirely invisible to non-speedsters.

How or why Savitar only appears to those connected to the Speed Force is yet to be explained, but if – oh, let’s say – Barry’s best pals were to suit up against said speedy big bad at an undetermined point in the future, it would probably look a lot like frantically tossing bolts in one-another’s direction, right? Heck, Cisco’s vibes are so filled with lens flares, you could probably even argue Savitar was visible in that shot.

The CW

Not to mention, while next week will definitely see Caitlin going a little rogue (in a Kevin Smith-directed hour), there’s no reason to believe she’d be fashioning her own costume just yet, let alone wearing it to fight Cisco out in the woods. In fact, if you notice in the “Killer Frost” trailer, Caitlin is not wearing her costume as she fires on Cisco (himself only wearing gauntlets and shades for now).

We’ll find out more as The Flash gears up for “Killer Frost” (don’t forget the big crossover after that, in which Caitlin was distinctly not seen in any footage), but what make we of Savitar’s invisibility? Will at least Wally be able to see him, or too evil to care?

Check Out 100 TV Facts You May Not Know!