The Flash Winter Promo: Killer Frost Arrives — With Earth-Two Barry/Iris?

“This is Ground Zero for ‘pretty messed up.'”

Truer words have probably never been spoken by The Flash‘s Joe West — and we’re not even sure if they came out of his mouth before or after the wildest goings-on in The CW’s new “Everything Will Change” promo for the second half of Season 2.

In the all-too-brief teaser, you’ll spy Caitlin’s Killer Frost alter ego emerging with wicked glee. There’s Barry and Iris either attending a retro costume party or (more likely) giving us a glimpse of their touchier, feelier Earth-Two selves.

And, as revealed earlier today, Matt Letscher is (somehow) back as Eobard Thawne aka Reverse-Flash.

The Flash returns to The CW on Tuesday, Jan. 19 (8/7c).

Excited about the new preview? Is “Everything Will Change” overselling it — or absolutely on-target? Sound off below!