Jesse Eisenberg and Kristen Stewart in American Ultra.

Jesse Eisenberg is having himself a great summer with this and his career-best performance in The End of the Tour. Eisenberg spreads his wings a bit as a stoner with a secret in American Ultra, this sporadically fun film from director Nima Nourizadeh (Project X) and writer Max Landis (Chronicle).

While enjoying a fine cup of soup, convenience-store clerk Mike Howell (Eisenberg) notices some dudes monkeying with his car. Seconds later, he’s killing people with a spoon. Mike’s girlfriend, Phoebe (Kristen Stewart, kicking mortal ass), is concerned about her beau, who has suddenly attained the ability to wipe out people with robot precision. I will not tell you why. You have to see the movie to find out why.

The film has a great premise, and it could’ve been a classic dark comedy. Unfortunately, it leans a little too heavy toward the dark side in its second half, and goes light on the laughs.

Eisenberg and Stewart rise above any of the tonal problems and lags in the story to make the movie something worth seeing. Stewart is getting better with every movie in which she shows up. I think her Bella-lag is wearing off, for sure. Eisenberg plays his part like an ignorant, coiled rattlesnake, and he’s appropriately scary at times.

This is a fun film for most of its running time—but it could’ve been something really special. 

American Ultra is playing at theaters across the valley.