The first rule about alien fight club is that you don’t talk about alien fight club — otherwise, you’re going to have some pesky superheroes show up and put a stop to the whole dang thing. That certainly was the case on the fourth episode of Supergirl’s sophomore season, “Survivors.”

Interestingly, this was not really an episode about Supergirl. Kara was maybe the sixth-most important character in the hour since the entire underground fighting ring really was a way to make the Martian Manhunter and Miss Martian’s conflict physical in Roulette’s cage matches.

Roulette, who is pretty much the same here as she is in the DC Comics, is a fun, savvy, and confident bad guy, though she mostly exists in order to get some folks with superpowers to fight, and fight they do.

Miss Martian, aka M’gann, is a willing participant in the matches and is unwilling to open up to J’onn. At first, it’s because he thinks she was hiding her participation in the fights from him but later comes to the conclusion that it’s because she feels guilty about surviving while the rest of their race died.

Of course, that’s wrong too, or at least it partially is. As the audience learns in the final shots of the episode, M’gann isn’t a Green Martian at all. She’s White Martian, and they’re traditionally villainous. J’onn does not have a good history with their kind, to say the least.

Maybe M’gann and J’onn will be able to learn from Mon-El and Kara, since their two species were historically bitter enemies. They’re getting to be friends now, though, after Mon-El’s ill-advised night on the town. We also learned what Mon-El’s powers are (he’s far weaker than Kara, but still plenty strong and able to leap tall buildings in a single bound). He was still able to help Kara out by giving her a tip on how to take down some of Roulette’s muscle.

That tip? Mon-El saw the fighter’s weakness on Warworld, a nasty gladiatorial planet from the comics ruled by Mongul. If that means we might visit Warworld on Supergirl (or have it visit us), it’ll certainly put Roulette’s dinky fights to shame.

Photos via DC Comics/Warner Bros. Television