When the Dominators arrive in the "Arrow"-verse, Flash and Green Arrow are going to a need a little help from their friend Supergirl. In a new "Supergirl"-centric poster for The CW's "Invasion!" crossover event, the Girl of Steel stands strong with Martian Manhunter at her side, even as the Dominators lurk in the background.

To the right stands her entryway to the "Arrow"-verse. "The Flash's" very own Cisco Ramon has the ability to break down the barriers between dimensions, and that's exactly what's happening here. This way, Supergirl can leave her own world and travel to the "Arrow"-verse. As seen in photos from next week's episode, it appears as though Barry "The Flash" Allen and Cisco show up in her world to recruit her to their cause.

RELATED: New Supergirl Photos Preview CW Crossover with Flash, Cisco

Once in the "Arrow"-verse, Supergirl will also join Green Arrow, the Legends of Tomorrow and their friends in order to stop an alien invasion. With them, she'll face down the Dominators, mind-controlling aliens who have grown so concerned about Earth's metahuman threat that they have decided to stomp it out before it can reach the stars.

Starring Melissa Benoist as the Girl of Steel, “Supergirl” airs Mondays at 8 pm ET/PT on The CW. The network is also home to Grant Gustin as the Scarlet Speedster in “The Flash,” airing Tuesdays at 8 pm ET/PT, Stephen Amell as the Emerald Archer in “Arrow,” airing Wednesdays at 8 pm ET/PT and Arthur Darvill, Brandon Routh and Caity Lotz in “DC’s Legends of Tomorrow,” airing Thursdays at 8 pm ET/PT.