Fresh off the departure of one of their own, Supergirl and the DEO will face a threat of seismic proportions in next week's episode of The CW series.

A promo for Season 5's fifth episode, titled "Dangerous Liaisons," sees a mysterious new villain steal a super-weapon that can cause massive tidal waves. With every coastal city in the world threatened, Brainiac 5 observes that millions of lives are in harm's way as a wave is poised to crash into National City.

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In addition to the powerful device, the villain is seen sporting mechanical arms, not unlike the classic Spider-Man antagonist Doctor Octopus.

The official synopsis for the episode, previously released by The CW, hinted that Supergirl will turn to an unlikely source for help as the coming terrorist attack targets a tech launch by new CatCo owner Andrea Rojas. Whether the new villain has a specific vendetta against the unscrupulous businesswoman remains to be seen.

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Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen and Chyler Leigh as Alex Danvers.