In the next episode of "Supergirl," Kara Danvers a.k.a. Supergirl (Melissa Benoist) attends Barry Allen a.k.a. The Flash (Grant Gustin) and Iris West's (Candice Patton) wedding which gets interrupted by villains from Earth-X.

The trailer and promotional photos for the upcoming installment titled "Crisis on Earth X, Part 1" was just recently released and showed Kara at the wedding together with other guests namely Oliver Queen a.k.a. Green Arrow (Stephen Amell), Felicity Smoak (Emily Bett Rickards), Sara Lance a.k.a. White Canary (Caity Lotz), and many others. Kara is shown sitting in the church beside her sister Alex (Chyler Leigh) as they watch the ceremony. Later, she takes the stage and shares her well wishes to the couple in front of the congregation. However, things do not go smoothly as villains from the Earth-X dimension infiltrate the universe and disrupt Allen and West's wedding.

The perpetrators, dressed in black suits with helmets and ski masks, barge in the church and threaten everyone with their guns. Everyone looks surprised as they start to run for cover. Heatwave a.k.a. Mick Rory (Dominic Purcell) hides behind a chair and waits for a good time to fight back against the intruders. Alex and Sara take matters into their hands and challenge the villains. It remains to be seen if Supergirl and the rest of the superheroes will be able to fend off the invaders from Earth-X.

In the last episode, Kara discovered her long-lost boyfriend Mon-El (Chris Wood) in a spaceship that crashed into the sea. She thought they would finally be together but it turned out that he fell in love with someone else and got married. Kara was taken aback by the revelation and felt bad that Mon-El was not honest about it.

"Supergirl" season 3 episode 8 will air on Monday, Nov. 27 at 9 p.m. EST on the CW.