One thing that bothered me about this movie was putting Frank Grillo on the poster, like he is a major character. He is not. He has what is basically a cameo at the very end. The only two characters other than other very secondary ones are Carrie-Anne Moss' and Douglas Smith's.
The story happens in a post-apocalyptic world in which some plant based virus infects people and make them attack and eat each other while slowly turning them into plants. Couchpotatosis, basically. The main character has amnesia and tries to find the girlfriend he lost after a car accident, while this old lady Mae helps him find her. And various things happen until he finds her. That's it.
However, the acting is really good, the sound, the sets, the atmosphere. I switched from "why does Carrie-Anne Moss play in all these stupid movies lately?" to "I got why she chose to play in this one". Douglas Smith did well, too, although I would say I can imagine the guy being like that in real life, so maybe he played himself :) A bit mean to say that.
Basically, an arthouse zombie flick, of which there are a lot for some reason, low budget, but well done.