Alien invaders launch a terrifying attack on the Lighthouse in the trailer for Agents of S.H.I.E.L.D.'s next episode, "Option Two." The battle to save Earth is clearly about to begin.

The clock is still ticking down to the end of the world in Agents of S.H.I.E.L.D. Season 5. The Kree are approaching Earth, and their arrival will ultimately lead to Hydra years ago. He will somehow protect the world from the Kree, if they give him both Inhumans and Gravitonium. Qovas's purpose and identity remain enigmatic, but it's clear he can't be trusted.

The last episode, "All Roads Lead...", saw General Hale reveal that S.H.I.E.L.D. now possess the Gravitonium. The result was never in doubt, and the trailer confirms that the Lighthouse is about to be invaded by a powerful alien force. Remarkably, Qovas's forces seem even more dangerous than the Kree warriors S.H.I.E.L.D. have fought before. "Wherever they go, darkness follows," Deke warns, evidently knowing these aliens from his own time.

It's still unclear just who Qovas is, but he seems to have forces within striking distance of Earth. In fact, given his chamber is typically shrouded in darkness, it's actually possible he's based on Earth. That makes Qovas and his alien warriors a terrifying and unexpected threat. Notice that they appear to use the same deadly chakram wielded by the ill-fated Ruby; Dove Cameron teased that they may be made of Vibranium. They're also fast, agile, and remarkably resilient. The trailer shows Qovas's warriors shrugging off bullets with apparent ease.

"This is how we lose," Yo-Yo declares. Given the last episode saw her believe she'd saved the world, that's a remarkable about-turn for the Inhuman super-speedster. She's certainly right about S.H.I.E.L.D. being hopelessly outgunned, though. Qovas's warriors possess the skill and power to tear through S.H.I.E.L.D.'s agents with ease. Even with Daisy and Yo-Yo on their side, S.H.I.E.L.D. will need every edge they can get to survive Qovas. It's possible this is the reason Daisy will undergo the particle infusion process - in order to save the world, she must risk it, and bond with the Gravitonium. That would certainly fit with the episode title, "Option Two."

There are only four episodes left of Agents of S.H.I.E.L.D. Season 5. It's still unknown whether or not the show will be renewed for a sixth season. ABC boss Channing Dungey has said she's "recent rumors that the network has voted in S.H.I.E.L.D.'s favor, but those are as yet unconfirmed.

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Agents of S.H.I.E.L.D. season 5 continues Friday April 27 with “Option Two” at 9pm on ABC.