SPOILER WARNING: This article contains spoilers for tonight’s episode of "Supergirl," titled "The Adventures of Supergirl," which has not concluded on the west coast as of publication.


Monday's second season premiere of "Supergirl" promised changes, no matter what -- new network (moving from CBS to The CW), new filming location (moving from Los Angeles to Vancouver), new Superman (guest star Tyler Hoechlin). Appropriately enough for any episode with the word adventure in the title, they saved some of the biggest developments for the final moments.

We've known that Metallo (Frederick Schmidt), DC Comics' classic Superman villain who clings to life by means of a Kryptonite heart, would be at least temporarily be joining the "Supergirl" roster for some time. What wasn't known, of course, was how, and now that answer is out there: it's through the looming specter of Project Cadmus, the shadowy government organization thought to be hiding Jeremiah Danvers, Kara's adoptive father. Barely alive after an encounter with the Super-cousins -- and, more specifically, after being shot by Lena Luthor (Katie McGrath) -- John Corben gets to choose whether or not he wants to stay alive (and blink once for yes).

With that, a mysterious administrator of the program (Brenda Strong) welcomes him to his new life, complete with metal laced through his system. It's a good bet that Kryptonite heart will make an appearance, and equally as likely he'll go toe to toe with Superman in next week's episode. What isn't known is exactly the role Strong's character will play, though that cool, calm, and collected voice that served her so well on "Desperate Housewives" would be an unsettling trait for any big bad.

Check back later for CBR’s full recap.

Starring Melissa Benoist as the title character, "Supergirl" airs Mondays at 8 pm ET/PT on The CW. The series also stars David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen, Chyler Leigh as Alex Danvers and Jeremy Jordan as Winn Schott and features appearances by Calista Flockhart's Cat Grant as well as Tyler Hoechlin's Superman.