After debuting two new posters at Comic-Con last week, Lionsgate has unveiled a clip from their upcoming action-comedy American Ultra. The scene features Phoebe (Kristen Stewart), hard at work at her bail bonds office, who gets a call from her boyfriend Mike (Jesse Eisenberg). He's freaking out at his convenience store job after killing two people with a spoon. While begging Phoebe to come over, Mike explains how he killed these assailants, and it's pretty gruesome. Then, even more trouble arrives. It's the police!

American Ultra is a fast-paced action comedy about Mike (Jesse Eisenberg), a seemingly hapless and unmotivated stoner whose small-town life with his live-in girlfriend, Phoebe (Kristen Stewart), is suddenly turned upside down. Unbeknownst to him, Mike is actually a highly trained, lethal sleeper agent. In the blink of an eye, as his secret past comes back to haunt him, Mike is thrust into the middle of a deadly government operation and is forced to summon his inner action-hero in order to survive.

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While we don't know for certain, it's possible that this clip shows how Mike first becomes aware of his secretive training as a sleeper agent. Unfortunately, this scene doesn't show Mike in action, putting his hidden skills to good use. Hopefully we'll see Mike in action sometime in the near future, as we get closer to the August 21 release date. One thing is for certain after watching this clip, though. Mike is very high-strung for a stoner. It's not hard to imagine that killing two people with skills one didn't know they had might take an unexpected toll on a person like Mike.

Walton Goggins, Topher Grace, Connie Britton, John Leguizamo, Bill Pullman and Tony Hale round out the supporting cast of American Ultra, arriving in theaters August 21. Nima Nourizadeh (Project X) directs this action comedy from a screenplay by Max Landis. This project also serves as a reunion for Kristen Stewart and Jesse Eisenberg, who both starred in the 2009 comedy Adventureland.

Like many movies released at the end of August, American Ultra has the potential to be a true sleeper hit, opening against Hitman: Agent 47 and Sinister 2. Do you think American Ultra could end up being the last summer blockbuster of 2015? Or do you think that title will go to the Fantastic Four remake, opening two weeks earlier on August 7? Let us know what you think after checking out the latest clip from American Ultra.