Kristen Stewart and Jesse Eisenberg star in the new slacker comedy drama 'American Ultra' and are featured in the movie's first new trailer.  (Photo: Sceencap)

Kristen Stewart and Jesse Eisenberg star in the new slacker comedy drama ‘American Ultra’ and are featured in the movie’s first new trailer. (Photo: Sceencap)

Kristen Stewart and Jesse Eisenberg take the D-Train back to Slackerville in a new red band trailer for their upcoming action-comedy “American Ultra.” They still possess the same old chemistry, but you gotta ask: What are they doing in a film like this?

The b-movie slacker formula worked well enough for them back in 2009 when they appeared in the comedy-drama “Adventureland.”

But Stewart was still a teenager in a role perfectly suited for someone just establishing themselves. Now, the 25-year-old actress is half way to 30, and seems just a little too old for the part. Ditto Eisenberg, who is 31. Yet, here they are.

Eisenberg plays stoner Mike Howell who seems content getting by on menial jobs as long as the pot holds out. Stewart plays Phoebe Larson, his equally directionless girlfriend. But there is a twist.

In a past life, buried in his subconscious, Eisenberg was a highly trained assassin. The problem is the government doesn’t want him around anymore after one of his handlers spills top secret information and “reactivates” him. Just try to kill the sucker, however.

No other trained assassin can come close. Even Howell doesn’t realize where his deadly skills are coming from. He’s just as afraid of them as his adversaries. But they come in handy when the bad guys come calling.

The Lionsgate film also stars Connie Britton, Topher Grace, John Leguizamo, Bill Pullman, Walton Goggins and Tony Hale.

Max Landis (“Chronicle”) wrote the script and Nima Nourizadeh (“Project X”) directed.

Eisenberg previously starred in “Zombieland” and “30 Minutes or Less,” so the film is right up his alley. Stewart has been appearing in far classier stuff since her “Twilight” days, like “Camp X-Ray,” “Still Alice” and “Clouds of Sils Maria,” for which she won a major French acting award.

Still, she’s talked about her desire to become an action-adventure star and even play a superhero character. So this may be her way of seguing into the genre.

The film is scheduled to be released on August 21. Check out the clip below, let us know your thoughts and be sure to follow IM on Twitter for the latest movie news.

Caution: The trailer has been red banded mainly for violence and language. No nudity.