While Plants Versus Zombies 2 might not be around the corner just yet, I'm wondering what the zombies are brewing to exact their revenge for the death of their ruler Dr. Edgar George Zomboss.
Homeowner seeks new haven (Left 4 Dead)
Sooner or later the homeowner (who you as a player assumes during the game) realizes his house and its plant is no longer up to the task of killing the zombies, which has inevitably outnumbered and overwhelmed them. After hearing word from other survivors, the homeowner explores the world for new species of plants usable against zombies. Perhaps a new home which grows the fruit of life?