By Natalie Abrams
March 19, 2017 at 07:02 PM EDT
The CW

“Best team-up ever!”

Felicity Smoak could not be more right. In a new extended trailer for the crossover between Arrow, The Flash, Supergirl, and DC’s Legends of Tomorrow, viewers get their first good look at the invasion of the Dominators, a technologically advanced alien race hellbent on quashing the threat posed by metahumans.

But the Dominators aren’t just coming to Earth to fight our favorites heroes; it’s more of a worldwide invasion. And the new trailer seems to indicate that the assembled heroes may not be able to survive this: Just listen to what sounds like Barry Allen bidding farewell as if he’s planning to die. Given that the clip also shows the heroes on what appears to be the alien aircraft, the future is looking pretty bleak.

Check out the promo for the epic four-way crossover, which kicks off Monday during Supergirl at 8 p.m. ET on The CW.