SPOILER WARNING: This article contains major spoilers for "Dead or Alive," the latest episode of "The Flash."

In "Dead or Alive," the latest episode of "The Flash," Cisco went for a spin around the multiverse. Considering the fact that he was fighting another viber at the time, it seems a little inevitable that he and his adversary Gypsy would end up jumping to other worlds as they engaged in a trial by combat, but one of the worlds they landed on will be very familiar to fans of the "Arrow"-verse.

During their fight, Gypsy and Cisco traveled to "Supergirl's" National City for a brief moment. They landed right smack dab in Cat Grant's -- now James Olsen's -- office at CatCo and destroyed a coffee table in the process. Though James wasn't around to witness the tussle, his secretary Miss Tessmacher was.

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As Cisco and Gypsy threw down, Tessmacher shrieked and hid behind her chair. The two vibers disappeared as quickly as they showed up, only for Tessmacher to whisper, "This city is getting crazier all the time."

"Supergirl's" world isn't the only one that Cisco and Gypsy visited. They also stopped by Earth-2, only for Gypsy to land a punch right on Cisco's face. Additionally, they visited a world that seemed ravaged by lava, where Gypsy held Cisco's head over a steep cliff.

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Ultimately, they brought the fight back to Earth-1, where Cisco was able to overcome Gypsy by exploiting her weakness. That is to say, Julian Albert noticed that she would jump out of the portals she vibed, which means there was a split second where she was suspended mid-air; Cisco seized this opportunity to knock her back and pinned her to the ground through the sheer force of his vibe blast. In this moment, he had an opportunity to kill her, but chose to spare her.

As a result, Gypsy returned to Earth-19 -- but, in order to salvage her reputation, she promised to tell her employers that HR Wells was dead. As such, HR cannot return to his world and must remain on Earth-1 for the time being.

Airing Tuesdays at 8 p.m. ET/PT on The CW, “The Flash” stars Grant Gustin, Candice Patton, Danielle Panabaker, Carlos Valdes, Tom Cavanagh, Jesse L. Martin and Keiynan Lonsdale.