American Ultra, built upon ridiculous premise and casting, is not only the funniest but unexpectedly one of the best action movies of the summer.

A loud, ugly, slapdash combination of action movie, pot comedy, criminal romance, and conspiracy thriller - and about as lumpy and ungainly as you'd imagine such a stew would be.

There are patches where the film stalls and crumbles under too much explanation. That's a shame, because the movie does have bite and sterling moments. But you shouldn't have to be stoned to appreciate them.

A rather exciting, downright visceral, very often romantic, and unexpectedly fun experience.